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24 .\" Copyright 2011 Joshua M. Clulow <josh@sysmgr.org>
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31 .TH zfs 8 "May 11, 2016" "ZFS pool 28, filesystem 5" "System Administration Commands"
33 zfs \- configures ZFS file systems
42 \fBzfs\fR \fBcreate\fR [\fB-p\fR] [\fB-o\fR \fIproperty\fR=\fIvalue\fR] ... \fIfilesystem\fR
47 \fBzfs\fR \fBcreate\fR [\fB-ps\fR] [\fB-b\fR \fIblocksize\fR] [\fB-o\fR \fIproperty\fR=\fIvalue\fR] ... \fB-V\fR \fIsize\fR \fIvolume\fR
52 \fBzfs\fR \fBdestroy\fR [\fB-fnpRrv\fR] \fIfilesystem\fR|\fIvolume\fR
57 \fBzfs\fR \fBdestroy\fR [\fB-dnpRrv\fR] \fIfilesystem\fR|\fIvolume\fR@\fIsnap\fR[%\fIsnap\fR][,...]
62 \fBzfs\fR \fBdestroy\fR \fIfilesystem\fR|\fIvolume\fR#\fIbookmark\fR
67 \fBzfs\fR \fBsnapshot | snap\fR [\fB-r\fR] [\fB-o\fR \fIproperty\fR=\fIvalue\fR] ...
68 \fIfilesystem@snapname\fR|\fIvolume@snapname\fR ...
73 \fBzfs\fR \fBrollback\fR [\fB-rRf\fR] \fIsnapshot\fR
78 \fBzfs\fR \fBclone\fR [\fB-p\fR] [\fB-o\fR \fIproperty\fR=\fIvalue\fR] ... \fIsnapshot\fR \fIfilesystem\fR|\fIvolume\fR
83 \fBzfs\fR \fBpromote\fR \fIclone-filesystem\fR
88 \fBzfs\fR \fBrename\fR [\fB-f\fR] \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR
89 \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR
94 \fBzfs\fR \fBrename\fR [\fB-fp\fR] \fIfilesystem\fR|\fIvolume\fR \fIfilesystem\fR|\fIvolume\fR
99 \fBzfs\fR \fBrename\fR \fB-r\fR \fIsnapshot\fR \fIsnapshot\fR
104 \fBzfs\fR \fBlist\fR [\fB-r\fR|\fB-d\fR \fIdepth\fR][\fB-Hp\fR][\fB-o\fR \fIproperty\fR[,\fIproperty\fR]...] [\fB-t\fR \fItype\fR[,\fItype\fR]..]
105 [\fB-s\fR \fIproperty\fR] ... [\fB-S\fR \fIproperty\fR] ... [\fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR|\fImountpoint\fR] ...
110 +\fBzfs\fR \fBset\fR \fIproperty\fR=\fIvalue\fR... \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR...
115 \fBzfs\fR \fBget\fR [\fB-r\fR|\fB-d\fR \fIdepth\fR][\fB-Hp\fR][\fB-o\fR \fIfield\fR[,...]] [\fB-t\fR \fItype\fR[,...]]
116 [\fB-s\fR \fIsource\fR[,...]] "\fIall\fR" | \fIproperty\fR[,...] \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR|\fImountpoint\fR ...
121 \fBzfs\fR \fBinherit\fR [\fB-rS\fR] \fIproperty\fR \fIfilesystem\fR|\fIvolume|snapshot\fR ...
126 \fBzfs\fR \fBupgrade\fR [\fB-v\fR]
131 \fBzfs\fR \fBupgrade\fR [\fB-r\fR] [\fB-V\fR \fIversion\fR] \fB-a\fR | \fIfilesystem\fR
136 \fBzfs\fR \fBuserspace\fR [\fB-Hinp\fR] [\fB-o\fR \fIfield\fR[,...]] [\fB-s\fR \fIfield\fR] ...
137 [\fB-S\fR \fIfield\fR] ... [\fB-t\fR \fItype\fR[,...]] \fIfilesystem\fR|\fIsnapshot\fR
142 \fBzfs\fR \fBgroupspace\fR [\fB-Hinp\fR] [\fB-o\fR \fIfield\fR[,...]] [\fB-s\fR \fIfield\fR] ...
143 [\fB-S\fR \fIfield\fR] ... [\fB-t\fR \fItype\fR[,...]] \fIfilesystem\fR|\fIsnapshot\fR
148 \fBzfs\fR \fBmount\fR
153 \fBzfs\fR \fBmount\fR [\fB-vO\fR] [\fB-o \fIoptions\fR\fR] \fB-a\fR | \fIfilesystem\fR
158 \fBzfs\fR \fBunmount | umount\fR [\fB-f\fR] \fB-a\fR | \fIfilesystem\fR|\fImountpoint\fR
163 \fBzfs\fR \fBshare\fR \fB-a\fR | \fIfilesystem\fR
168 \fBzfs\fR \fBunshare\fR \fB-a\fR \fIfilesystem\fR|\fImountpoint\fR
173 \fBzfs\fR \fBbookmark\fR \fIsnapshot\fR \fIbookmark\fR
178 \fBzfs\fR \fBsend\fR [\fB-DnPpRveL\fR] [\fB-\fR[\fBiI\fR] \fIsnapshot\fR] \fIsnapshot\fR
183 \fBzfs\fR \fBsend\fR [\fB-eL\fR] [\fB-i \fIsnapshot\fR|\fIbookmark\fR]\fR \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR
188 \fBzfs\fR \fBreceive\fR [\fB-vnFu\fR] [\fB-o origin\fR=\fIsnapshot\fR] \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR
193 \fBzfs\fR \fBreceive\fR [\fB-vnFu\fR] [\fB-d\fR|\fB-e\fR] [\fB-o origin\fR=\fIsnapshot\fR] \fIfilesystem\fR
198 \fBzfs\fR \fBallow\fR \fIfilesystem\fR|\fIvolume\fR
203 \fBzfs\fR \fBallow\fR [\fB-ldug\fR] "\fIeveryone\fR"|\fIuser\fR|\fIgroup\fR[,...] \fIperm\fR|\fI@setname\fR[,...]
204 \fIfilesystem\fR|\fIvolume\fR
209 \fBzfs\fR \fBallow\fR [\fB-ld\fR] \fB-e\fR \fIperm\fR|@\fIsetname\fR[,...] \fIfilesystem\fR|\fIvolume\fR
214 \fBzfs\fR \fBallow\fR \fB-c\fR \fIperm\fR|@\fIsetname\fR[,...] \fIfilesystem\fR|\fIvolume\fR
219 \fBzfs\fR \fBallow\fR \fB-s\fR @\fIsetname\fR \fIperm\fR|@\fIsetname\fR[,...] \fIfilesystem\fR|\fIvolume\fR
224 \fBzfs\fR \fBunallow\fR [\fB-rldug\fR] "\fIeveryone\fR"|\fIuser\fR|\fIgroup\fR[,...] [\fIperm\fR|@\fIsetname\fR[,... ]]
225 \fIfilesystem\fR|\fIvolume\fR
230 \fBzfs\fR \fBunallow\fR [\fB-rld\fR] \fB-e\fR [\fIperm\fR|@\fIsetname\fR[,... ]] \fIfilesystem\fR|\fIvolume\fR
235 \fBzfs\fR \fBunallow\fR [\fB-r\fR] \fB-c\fR [\fIperm\fR|@\fIsetname\fR[ ... ]] \fIfilesystem\fR|\fIvolume\fR
240 \fBzfs\fR \fBunallow\fR [\fB-r\fR] \fB-s\fR @\fIsetname\fR [\fIperm\fR|@\fIsetname\fR[,... ]] \fIfilesystem\fR|\fIvolume\fR
245 \fBzfs\fR \fBhold\fR [\fB-r\fR] \fItag\fR \fIsnapshot\fR...
250 \fBzfs\fR \fBholds\fR [\fB-r\fR] \fIsnapshot\fR...
255 \fBzfs\fR \fBrelease\fR [\fB-r\fR] \fItag\fR \fIsnapshot\fR...
260 \fBzfs\fR \fBdiff\fR [\fB-FHt\fR] \fIsnapshot\fR \fIsnapshot|filesystem\fR
264 The \fBzfs\fR command configures \fBZFS\fR datasets within a \fBZFS\fR storage pool, as described in \fBzpool\fR(8). A dataset is identified by a unique path within the \fBZFS\fR namespace. For example:
268 pool/{filesystem,volume,snapshot}
275 where the maximum length of a dataset name is \fBMAXNAMELEN\fR (256 bytes).
278 A dataset can be one of the following:
282 \fB\fIfilesystem\fR\fR
286 A \fBZFS\fR dataset of type \fBfilesystem\fR can be mounted within the standard system namespace and behaves like other file systems. While \fBZFS\fR file systems are designed to be \fBPOSIX\fR compliant, known issues exist that prevent compliance in some cases. Applications that depend on standards conformance might fail due to nonstandard behavior when checking file system free space.
296 A logical volume exported as a raw or block device. This type of dataset should only be used under special circumstances. File systems are typically used in most environments.
306 A read-only version of a file system or volume at a given point in time. It is specified as \fIfilesystem@name\fR or \fIvolume@name\fR.
316 Much like a \fIsnapshot\fR, but without the hold on on-disk data. It can be used as the source of a send (but not for a receive).
317 It is specified as \fIfilesystem#name\fR or \fIvolume#name\fR.
320 .SS "ZFS File System Hierarchy"
322 A \fBZFS\fR storage pool is a logical collection of devices that provide space for datasets. A storage pool is also the root of the \fBZFS\fR file system hierarchy.
325 The root of the pool can be accessed as a file system, such as mounting and unmounting, taking snapshots, and setting properties. The physical storage characteristics, however, are managed by the \fBzpool\fR(8) command.
328 See \fBzpool\fR(8) for more information on creating and administering pools.
331 A snapshot is a read-only copy of a file system or volume. Snapshots can be created extremely quickly, and initially consume no additional space within the pool. As data within the active dataset changes, the snapshot consumes more data than would otherwise be shared with the active dataset.
334 Snapshots can have arbitrary names. Snapshots of volumes can be cloned or rolled back. Visibility is determined by the \fBsnapdev\fR property of the parent volume.
337 File system snapshots can be accessed under the \fB\&.zfs/snapshot\fR directory in the root of the file system. Snapshots are automatically mounted on demand and may be unmounted at regular intervals. The visibility of the \fB\&.zfs\fR directory can be controlled by the \fBsnapdir\fR property.
340 A bookmark is like a snapshot, a read-only copy of a file system or volume. Bookmarks can be created extremely quickly, compared to snapshots, and they consume no additional space within the pool. Bookmarks can also have arbitrary names, much like snapshots.
343 Unlike snapshots, bookmarks can not be accessed through the filesystem in any way. From a storage standpoint a bookmark just provides a way to reference when a snapshot was created as a distinct object. Bookmarks are initially tied to a snapshot, not the filesystem/volume, and they will survive if the snapshot itself is destroyed. Since they are very light weight there's little incentive to destroy them.
346 A clone is a writable volume or file system whose initial contents are the same as another dataset. As with snapshots, creating a clone is nearly instantaneous, and initially consumes no additional space.
349 Clones can only be created from a snapshot. When a snapshot is cloned, it creates an implicit dependency between the parent and child. Even though the clone is created somewhere else in the dataset hierarchy, the original snapshot cannot be destroyed as long as a clone exists. The \fBorigin\fR property exposes this dependency, and the \fBdestroy\fR command lists any such dependencies, if they exist.
352 The clone parent-child dependency relationship can be reversed by using the \fBpromote\fR subcommand. This causes the "origin" file system to become a clone of the specified file system, which makes it possible to destroy the file system that the clone was created from.
355 Creating a \fBZFS\fR file system is a simple operation, so the number of file systems per system is likely to be numerous. To cope with this, \fBZFS\fR automatically manages mounting and unmounting file systems without the need to edit the \fB/etc/fstab\fR file. All automatically managed file systems are mounted by \fBZFS\fR at boot time.
358 By default, file systems are mounted under \fB/\fIpath\fR\fR, where \fIpath\fR is the name of the file system in the \fBZFS\fR namespace. Directories are created and destroyed as needed.
361 A file system can also have a mount point set in the \fBmountpoint\fR property. This directory is created as needed, and \fBZFS\fR automatically mounts the file system when the \fBzfs mount -a\fR command is invoked (without editing \fB/etc/fstab\fR). The \fBmountpoint\fR property can be inherited, so if \fBpool/home\fR has a mount point of \fB/export/stuff\fR, then \fBpool/home/user\fR automatically inherits a mount point of \fB/export/stuff/user\fR.
364 A file system \fBmountpoint\fR property of \fBnone\fR prevents the file system from being mounted.
367 If needed, \fBZFS\fR file systems can also be managed with traditional tools (\fBmount\fR, \fBumount\fR, \fB/etc/fstab\fR). If a file system's mount point is set to \fBlegacy\fR, \fBZFS\fR makes no attempt to manage the file system, and the administrator is responsible for mounting and unmounting the file system.
370 Deduplication is the process for removing redundant data at the block-level, reducing the total amount of data stored. If a file system has the \fBdedup\fR property enabled, duplicate data blocks are removed synchronously. The result is that only unique data is stored and common components are shared among files.
372 \fBWARNING: DO NOT ENABLE DEDUPLICATION UNLESS YOU NEED IT AND KNOW EXACTLY WHAT YOU ARE DOING!\fR
374 Deduplicating data is a very resource-intensive operation. It is generally recommended that you have \fIat least\fR 1.25 GiB of RAM per 1 TiB of storage when you enable deduplication. But calculating the exact requirements is a somewhat complicated affair.
376 Enabling deduplication on an improperly-designed system will result in extreme performance issues (extremely slow filesystem and snapshot deletions etc.) and can potentially lead to data loss (i.e. unimportable pool due to memory exhaustion) if your system is not built for this purpose. Deduplication affects the processing power (CPU), disks (and the controller) as well as primary (real) memory.
378 Before creating a pool with deduplication enabled, ensure that you have planned your hardware requirements appropriately and implemented appropriate recovery practices, such as regular backups.
380 Unless necessary, deduplication should NOT be enabled on a system. Instead, consider using \fIcompression=lz4\fR, as a less resource-intensive alternative.
384 Properties are divided into two types: native properties and user-defined (or "user") properties. Native properties either export internal statistics or control \fBZFS\fR behavior. User properties have no effect on \fBZFS\fR behavior, but you can use them to annotate datasets and snapshots in a way that is meaningful in your environment.
387 Properties are generally inherited from the parent unless overridden by the child. See the documentation below for exceptions.
390 .SS "Native Properties"
391 Native properties apply to all dataset types unless otherwise noted. However, native properties cannot be edited on snapshots.
394 The values of numeric native properties can be specified using human-readable abbreviations (\fBK\fR, \fBM\fR, \fBG\fR, \fBT\fR, \fBP\fR, \fBE\fR, and \fBZ\fR). These abbreviations can optionally use the IEC binary prefixes (e.g. GiB) or SI decimal prefixes (e.g. GB), though the SI prefixes are treated as binary prefixes. Abbreviations are case-insensitive. The following are all valid (and equal) specifications:
398 1536M, 1.5g, 1.50GB, 1.5GiB
405 The values of non-numeric native properties are case-sensitive and must be lowercase, except for \fBmountpoint\fR, \fBsharenfs\fR, and \fBsharesmb\fR.
408 The following native properties consist of read-only statistics about the dataset. These properties can be neither set, nor inherited.
412 \fB\fBavailable\fR\fR
416 The amount of space available to the dataset and all its children, assuming that there is no other activity in the pool. Because space is shared within a pool, availability can be limited by any number of factors, including physical pool size, quotas, reservations, or other datasets within the pool.
418 This property can also be referred to by its shortened column name, \fBavail\fR.
424 \fB\fBcompressratio\fR\fR
428 For non-snapshots, the compression ratio achieved for the \fBused\fR space of this dataset, expressed as a multiplier. The \fBused\fR property includes descendant datasets, and, for clones, does not include the space shared with the origin snapshot. For snapshots, the \fBcompressratio\fR is the same as the \fBrefcompressratio\fR property. The \fBcompression\fR property controls whether compression is enabled on a dataset.
438 The time this dataset was created.
448 For snapshots, this property is a comma-separated list of filesystems or
449 volumes which are clones of this snapshot. The clones' \fBorigin\fR property
450 is this snapshot. If the \fBclones\fR property is not empty, then this
451 snapshot can not be destroyed (even with the \fB-r\fR or \fB-f\fR options). The
452 roles of origin and clone can be swapped by promoting the clone with the
453 \fBzfs promote\fR command.
459 \fB\fBdefer_destroy\fR\fR
463 This property is \fBon\fR if the snapshot has been marked for deferred destruction by using the \fBzfs destroy\fR \fB-d\fR command. Otherwise, the property is \fBoff\fR.
469 \fB\fBfilesystem_count\fR
473 The total number of filesystems and volumes that exist under this location in the
474 dataset tree. This value is only available when a \fBfilesystem_limit\fR has
475 been set somewhere in the tree under which the dataset resides.
481 \fB\fBlogicalreferenced\fR\fR
485 The amount of space that is "logically" accessible by this dataset. See
486 the \fBreferenced\fR property. The logical space ignores the effect of
487 the \fBcompression\fR and \fBcopies\fR properties, giving a quantity
488 closer to the amount of data that applications see. However, it does
489 include space consumed by metadata.
491 This property can also be referred to by its shortened column name,
498 \fB\fBlogicalused\fR\fR
502 The amount of space that is "logically" consumed by this dataset and all
503 its descendents. See the \fBused\fR property. The logical space
504 ignores the effect of the \fBcompression\fR and \fBcopies\fR properties,
505 giving a quantity closer to the amount of data that applications see.
506 However, it does include space consumed by metadata.
508 This property can also be referred to by its shortened column name,
519 For file systems, indicates whether the file system is currently mounted. This property can be either \fByes\fR or \fBno\fR.
529 For cloned file systems or volumes, the snapshot from which the clone was created. The origin cannot be destroyed (even with the \fB-r\fR or \fB-f\fR options) so long as a clone exists. See also the \fBclones\fR property.
535 \fB\fBreferenced\fR\fR
539 The amount of data that is accessible by this dataset, which may or may not be shared with other datasets in the pool. When a snapshot or clone is created, it initially references the same amount of space as the file system or snapshot it was created from, since its contents are identical.
541 This property can also be referred to by its shortened column name, \fBrefer\fR.
547 \fB\fBrefcompressratio\fR\fR
551 The compression ratio achieved for the \fBreferenced\fR space of this
552 dataset, expressed as a multiplier. See also the \fBcompressratio\fR
559 \fB\fBsnapshot_count\fR
563 The total number of snapshots that exist under this location in the dataset tree.
564 This value is only available when a \fBsnapshot_limit\fR has been set somewhere
565 in the tree under which the dataset resides.
575 The type of dataset: \fBfilesystem\fR, \fBvolume\fR, or \fBsnapshot\fR.
585 The amount of space consumed by this dataset and all its descendents. This is the value that is checked against this dataset's quota and reservation. The space used does not include this dataset's reservation, but does take into account the reservations of any descendent datasets. The amount of space that a dataset consumes from its parent, as well as the amount of space that are freed if this dataset is recursively destroyed, is the greater of its space used and its reservation.
587 When snapshots (see the "Snapshots" section) are created, their space is initially shared between the snapshot and the file system, and possibly with previous snapshots. As the file system changes, space that was previously shared becomes unique to the snapshot, and counted in the snapshot's space used. Additionally, deleting snapshots can increase the amount of space unique to (and used by) other snapshots.
589 The amount of space used, available, or referenced does not take into account pending changes. Pending changes are generally accounted for within a few seconds. Committing a change to a disk using \fBfsync\fR(2) or \fBO_SYNC\fR (see \fBopen\fR(2)) does not necessarily guarantee that the space usage information is updated immediately.
599 The \fBusedby*\fR properties decompose the \fBused\fR properties into the various reasons that space is used. Specifically, \fBused\fR = \fBusedbychildren\fR + \fBusedbydataset\fR + \fBusedbyrefreservation\fR + \fBusedbysnapshots\fR. These properties are only available for datasets created on \fBzpool\fR version 13 or higher pools.
605 \fB\fBusedbychildren\fR\fR
609 The amount of space used by children of this dataset, which would be freed if all the dataset's children were destroyed.
615 \fB\fBusedbydataset\fR\fR
619 The amount of space used by this dataset itself, which would be freed if the dataset were destroyed (after first removing any \fBrefreservation\fR and destroying any necessary snapshots or descendents).
625 \fB\fBusedbyrefreservation\fR\fR
629 The amount of space used by a \fBrefreservation\fR set on this dataset, which would be freed if the \fBrefreservation\fR was removed.
635 \fB\fBusedbysnapshots\fR\fR
639 The amount of space consumed by snapshots of this dataset. In particular, it is the amount of space that would be freed if all of this dataset's snapshots were destroyed. Note that this is not simply the sum of the snapshots' \fBused\fR properties because space can be shared by multiple snapshots.
645 \fB\fBuserused@\fR\fIuser\fR\fR
649 The amount of space consumed by the specified user in this dataset. Space is charged to the owner of each file, as displayed by \fBls\fR \fB-l\fR. The amount of space charged is displayed by \fBdu\fR and \fBls\fR \fB-s\fR. See the \fBzfs userspace\fR subcommand for more information.
651 Unprivileged users can access only their own space usage. The root user, or a user who has been granted the \fBuserused\fR privilege with \fBzfs allow\fR, can access everyone's usage.
653 The \fBuserused@\fR... properties are not displayed by \fBzfs get all\fR. The user's name must be appended after the \fB@\fR symbol, using one of the following forms:
658 \fIPOSIX name\fR (for example, \fBjoe\fR)
664 \fIPOSIX numeric ID\fR (for example, \fB789\fR)
670 \fISID name\fR (for example, \fBjoe.smith@mydomain\fR)
676 \fISID numeric ID\fR (for example, \fBS-1-123-456-789\fR)
679 Files created on Linux always have POSIX owners.
688 This property is set to the number of user holds on this snapshot. User holds are set by using the \fBzfs hold\fR command.
694 \fB\fBgroupused@\fR\fIgroup\fR\fR
698 The amount of space consumed by the specified group in this dataset. Space is charged to the group of each file, as displayed by \fBls\fR \fB-l\fR. See the \fBuserused@\fR\fIuser\fR property for more information.
700 Unprivileged users can only access their own groups' space usage. The root user, or a user who has been granted the \fBgroupused\fR privilege with \fBzfs allow\fR, can access all groups' usage.
706 \fB\fBvolblocksize\fR=\fIblocksize\fR\fR
710 This property, which is only valid on volumes, specifies the block size of the volume. Any power of two from 512B to 128KiB is valid. The default is 8KiB.
712 This property cannot be changed after the volume is created.
714 This property can also be referred to by its shortened column name, \fBvolblock\fR.
724 The amount of \fBreferenced\fR space written to this dataset since the
731 \fB\fBwritten@\fR\fIsnapshot\fR\fR
735 The amount of \fBreferenced\fR space written to this dataset since the
736 specified snapshot. This is the space that is referenced by this dataset
737 but was not referenced by the specified snapshot.
739 The \fIsnapshot\fR may be specified as a short snapshot name (just the part
740 after the \fB@\fR), in which case it will be interpreted as a snapshot in
741 the same filesystem as this dataset.
742 The \fIsnapshot\fR be a full snapshot name (\fIfilesystem\fR@\fIsnapshot\fR),
743 which for clones may be a snapshot in the origin's filesystem (or the origin
744 of the origin's filesystem, etc).
749 The following native properties can be used to change the behavior of a \fBZFS\fR dataset.
753 \fB\fBaclinherit\fR=\fBrestricted\fR | \fBdiscard\fR | \fBnoallow\fR | \fBpassthrough\fR | \fBpassthrough-x\fR\fR
757 Controls how \fBACL\fR entries are inherited when files and directories are created. A file system with an \fBaclinherit\fR property of \fBdiscard\fR does not inherit any \fBACL\fR entries. A file system with an \fBaclinherit\fR property value of \fBnoallow\fR only inherits inheritable \fBACL\fR entries that specify "deny" permissions. The property value \fBrestricted\fR (the default) removes the \fBwrite_acl\fR and \fBwrite_owner\fR permissions when the \fBACL\fR entry is inherited. A file system with an \fBaclinherit\fR property value of \fBpassthrough\fR inherits all inheritable \fBACL\fR entries without any modifications made to the \fBACL\fR entries when they are inherited. A file system with an \fBaclinherit\fR property value of \fBpassthrough-x\fR has the same meaning as \fBpassthrough\fR, except that the \fBowner@\fR, \fBgroup@\fR, and \fBeveryone@\fR \fBACE\fRs inherit the execute permission only if the file creation mode also requests the execute bit.
759 When the property value is set to \fBpassthrough\fR, files are created with a mode determined by the inheritable \fBACE\fRs. If no inheritable \fBACE\fRs exist that affect the mode, then the mode is set in accordance to the requested mode from the application.
761 The \fBaclinherit\fR property does not apply to Posix ACLs.
767 \fB\fBacltype\fR=\fBoff\fR | \fBnoacl\fR | \fBposixacl\fR \fR
771 Controls whether ACLs are enabled and if so what type of ACL to use. When
772 a file system has the \fBacltype\fR property set to \fBoff\fR (the default)
773 then ACLs are disabled. Setting the \fBacltype\fR property to \fBposixacl\fR
774 indicates Posix ACLs should be used. Posix ACLs are specific to Linux and
775 are not functional on other platforms. Posix ACLs are stored as an xattr and
776 therefore will not overwrite any existing ZFS/NFSv4 ACLs which may be set.
777 Currently only \fBposixacls\fR are supported on Linux.
779 To obtain the best performance when setting \fBposixacl\fR users are strongly
780 encouraged to set the \fBxattr=sa\fR property. This will result in the
781 Posix ACL being stored more efficiently on disk. But as a consequence of this
782 all new xattrs will only be accessible from ZFS implementations which support
783 the \fBxattr=sa\fR property. See the \fBxattr\fR property for more details.
785 The value \fBnoacl\fR is an alias for \fBoff\fR.
791 \fB\fBatime\fR=\fBon\fR | \fBoff\fR\fR
795 Controls whether the access time for files is updated when they are read. Setting this property to \fBoff\fR avoids producing write traffic when reading files and can result in significant performance gains, though it might confuse mailers and other similar utilities. The default value is \fBon\fR. See also \fBrelatime\fR below.
797 The values \fBon\fR and \fBoff\fR are equivalent to the \fBatime\fR and \fBnoatime\fR mount options.
803 \fB\fBcanmount\fR=\fBon\fR | \fBoff\fR | \fBnoauto\fR\fR
807 If this property is set to \fBoff\fR, the file system cannot be mounted, and is ignored by \fBzfs mount -a\fR. Setting this property to \fBoff\fR is similar to setting the \fBmountpoint\fR property to \fBnone\fR, except that the dataset still has a normal \fBmountpoint\fR property, which can be inherited. Setting this property to \fBoff\fR allows datasets to be used solely as a mechanism to inherit properties. One example of setting \fBcanmount=\fR\fBoff\fR is to have two datasets with the same \fBmountpoint\fR, so that the children of both datasets appear in the same directory, but might have different inherited characteristics.
809 When the \fBnoauto\fR option is set, a dataset can only be mounted and unmounted explicitly. The dataset is not mounted automatically when the dataset is created or imported, nor is it mounted by the \fBzfs mount -a\fR command or unmounted by the \fBzfs unmount -a\fR command.
811 This property is not inherited. Every dataset defaults to \fBon\fR independently.
813 The values \fBon\fR and \fBnoauto\fR are equivalent to the \fBauto\fR and \fBnoauto\fR mount options.
819 \fB\fBchecksum\fR=\fBon\fR | \fBoff\fR | \fBfletcher2\fR | \fBfletcher4\fR | \fBsha256\fR\fR
823 Controls the checksum used to verify data integrity. The default value is \fBon\fR, which automatically selects an appropriate algorithm (currently, \fBfletcher4\fR, but this may change in future releases). The value \fBoff\fR disables integrity checking on user data. Disabling checksums is \fBNOT\fR a recommended practice.
825 Changing this property affects only newly-written data.
831 \fB\fBcompression\fR=\fBoff\fR | \fBon\fR | \fBlzjb\fR | \fBlz4\fR |
832 \fBgzip\fR | \fBgzip-\fR\fIN\fR | \fBzle\fR\fR
836 Controls the compression algorithm used for this dataset.
838 Setting compression to \fBon\fR indicates that the current default
839 compression algorithm should be used. The default balances compression
840 and decompression speed, with compression ratio and is expected to
841 work well on a wide variety of workloads. Unlike all other settings for
842 this property, \fBon\fR does not select a fixed compression type. As
843 new compression algorithms are added to ZFS and enabled on a pool, the
844 default compression algorithm may change. The current default compression
845 algorithm is either \fBlzjb\fR or, if the \fBlz4_compress\fR feature is
848 The \fBlzjb\fR compression algorithm is optimized for performance while
849 providing decent data compression.
851 The \fBlz4\fR compression algorithm is a high-performance replacement
852 for the \fBlzjb\fR algorithm. It features significantly faster
853 compression and decompression, as well as a moderately higher
854 compression ratio than \fBlzjb\fR, but can only be used on pools with
855 the \fBlz4_compress\fR feature set to \fIenabled\fR. See
856 \fBzpool-features\fR(5) for details on ZFS feature flags and the
857 \fBlz4_compress\fR feature.
859 The \fBgzip\fR compression algorithm uses the same compression as
860 the \fBgzip\fR(1) command. You can specify the \fBgzip\fR level by using the
861 value \fBgzip-\fR\fIN\fR where \fIN\fR is an integer from 1 (fastest) to 9
862 (best compression ratio). Currently, \fBgzip\fR is equivalent to \fBgzip-6\fR
863 (which is also the default for \fBgzip\fR(1)). The \fBzle\fR compression
864 algorithm compresses runs of zeros.
866 This property can also be referred to by its shortened column name
867 \fBcompress\fR. Changing this property affects only newly-written data.
873 \fB\fBcopies\fR=\fB1\fR | \fB2\fR | \fB3\fR\fR
877 Controls the number of copies of data stored for this dataset. These copies are in addition to any redundancy provided by the pool, for example, mirroring or RAID-Z. The copies are stored on different disks, if possible. The space used by multiple copies is charged to the associated file and dataset, changing the \fBused\fR property and counting against quotas and reservations.
879 Changing this property only affects newly-written data.
881 Remember that \fBZFS\fR will not import a pool with a missing top-level vdev. Do NOT create, for example, a two-disk, striped pool and set \fBcopies=\fR\fI2\fR on some datasets thinking you have setup redundancy for them. When one disk dies, you will not be able to import the pool and will have lost all of your data.
887 \fB\fBdedup\fR=\fBoff\fR | \fBon\fR | \fBverify\fR | \fBsha256\fR[,\fBverify\fR]\fR
891 Controls whether deduplication is in effect for a dataset. The default value is \fBoff\fR. The default checksum used for deduplication is \fBsha256\fR (subject to change). When \fBdedup\fR is enabled, the \fBdedup\fR checksum algorithm overrides the \fBchecksum\fR property. Setting the value to \fBverify\fR is equivalent to specifying \fBsha256,verify\fR.
893 If the property is set to \fBverify\fR, then, whenever two blocks have the same signature, ZFS will do a byte-for-byte comparison with the existing block to ensure that the contents are identical.
895 Unless necessary, deduplication should NOT be enabled on a system. See \fBDeduplication\fR above.
901 \fB\fBdevices\fR=\fBon\fR | \fBoff\fR\fR
905 Controls whether device nodes can be opened on this file system. The default value is \fBon\fR.
907 The values \fBon\fR and \fBoff\fR are equivalent to the \fBdev\fR and \fBnodev\fR mount options.
913 \fB\fBexec\fR=\fBon\fR | \fBoff\fR\fR
917 Controls whether processes can be executed from within this file system. The default value is \fBon\fR.
919 The values \fBon\fR and \fBoff\fR are equivalent to the \fBexec\fR and \fBnoexec\fR mount options.
925 \fB\fBmlslabel\fR=\fBnone\fR\fR | \fIlabel\fR
929 The \fBmlslabel\fR property is a sensitivity label that determines if a dataset can be mounted in a zone on a system with Trusted Extensions enabled. If the labeled dataset matches the labeled zone, the dataset can be mounted and accessed from the labeled zone.
931 When the \fBmlslabel\fR property is not set, the default value is \fBnone\fR. Setting the \fBmlslabel\fR property to \fBnone\fR is equivalent to removing the property.
933 The \fBmlslabel\fR property can be modified only when Trusted Extensions is enabled and only with appropriate privilege. Rights to modify it cannot be delegated. When changing a label to a higher label or setting the initial dataset label, the \fB{PRIV_FILE_UPGRADE_SL}\fR privilege is required. When changing a label to a lower label or the default (\fBnone\fR), the \fB{PRIV_FILE_DOWNGRADE_SL}\fR privilege is required. Changing the dataset to labels other than the default can be done only when the dataset is not mounted. When a dataset with the default label is mounted into a labeled-zone, the mount operation automatically sets the \fBmlslabel\fR property to the label of that zone.
935 When Trusted Extensions is \fBnot\fR enabled, only datasets with the default label (\fBnone\fR) can be mounted.
937 Zones are a Solaris feature and are not relevant on Linux.
943 \fB\fBfilesystem_limit\fR=\fBnone\fR\fR | \fIcount\fR
947 Limits the number of filesystems and volumes that can exist under this point in
948 the dataset tree. The limit is not enforced if the user is allowed to change
949 the limit. Setting a filesystem_limit on a descendent of a filesystem that
950 already has a filesystem_limit does not override the ancestor's filesystem_limit,
951 but rather imposes an additional limit. This feature must be enabled to be used
952 (see \fBzpool-features\fR(5)).
958 \fB\fBmountpoint\fR=\fIpath\fR | \fBnone\fR | \fBlegacy\fR\fR
962 Controls the mount point used for this file system. See the "Mount Points" section for more information on how this property is used.
964 When the \fBmountpoint\fR property is changed for a file system, the file system and any children that inherit the mount point are unmounted. If the new value is \fBlegacy\fR, then they remain unmounted. Otherwise, they are automatically remounted in the new location if the property was previously \fBlegacy\fR or \fBnone\fR, or if they were mounted before the property was changed. In addition, any shared file systems are unshared and shared in the new location.
970 \fB\fBnbmand\fR=\fBoff\fR | \fBon\fR\fR
974 Controls whether the file system should be mounted with \fBnbmand\fR (Non Blocking mandatory locks). This is used for \fBCIFS\fR clients. Changes to this property only take effect when the file system is umounted and remounted. See \fBmount\fR(1M) on a Solaris system for more information on \fBnbmand\fR mounts.
976 The values \fBon\fR and \fBoff\fR are equivalent to the \fBnbmand\fR and \fBnonbmand\fR mount options.
978 This property is not used on Linux.
984 \fB\fBprimarycache\fR=\fBall\fR | \fBnone\fR | \fBmetadata\fR\fR
988 Controls what is cached in the primary cache (ARC). If this property is set to \fBall\fR, then both user data and metadata is cached. If this property is set to \fBnone\fR, then neither user data nor metadata is cached. If this property is set to \fBmetadata\fR, then only metadata is cached. The default value is \fBall\fR.
994 \fB\fBquota\fR=\fBnone\fR | \fIsize\fR\fR
998 Limits the amount of space a dataset and its descendents can consume. This property enforces a hard limit on the amount of space used. This includes all space consumed by descendents, including file systems and snapshots. Setting a quota on a descendent of a dataset that already has a quota does not override the ancestor's quota, but rather imposes an additional limit.
1000 Quotas cannot be set on volumes, as the \fBvolsize\fR property acts as an implicit quota.
1006 \fB\fBsnapshot_limit\fR=\fBnone\fR\fR | \fIcount\fR
1010 Limits the number of snapshots that can be created on a dataset and its
1011 descendents. Setting a snapshot_limit on a descendent of a dataset that already
1012 has a snapshot_limit does not override the ancestor's snapshot_limit, but
1013 rather imposes an additional limit. The limit is not enforced if the user is
1014 allowed to change the limit. For example, this means that recursive snapshots
1015 taken from the global zone are counted against each delegated dataset within
1016 a zone. This feature must be enabled to be used (see \fBzpool-features\fR(5)).
1022 \fB\fBuserquota@\fR\fIuser\fR=\fBnone\fR | \fIsize\fR\fR
1026 Limits the amount of space consumed by the specified user. Similar to the \fBrefquota\fR property, the \fBuserquota\fR space calculation does not include space that is used by descendent datasets, such as snapshots and clones. User space consumption is identified by the \fBuserspace@\fR\fIuser\fR property. See the \fBzfs userspace\fR subcommand for more information.
1028 Enforcement of user quotas may be delayed by several seconds. This delay means that a user might exceed their quota before the system notices that they are over quota and begins to refuse additional writes with the \fBEDQUOT\fR error message.
1030 Unprivileged users can only access their own groups' space usage. The root user, or a user who has been granted the \fBuserquota\fR privilege with \fBzfs allow\fR, can get and set everyone's quota.
1032 This property is not available on volumes, on file systems before version 4, or on pools before version 15. The \fBuserquota@\fR... properties are not displayed by \fBzfs get all\fR. The user's name must be appended after the \fB@\fR symbol, using one of the following forms:
1037 \fIPOSIX name\fR (for example, \fBjoe\fR)
1043 \fIPOSIX numeric ID\fR (for example, \fB789\fR)
1049 \fISID name\fR (for example, \fBjoe.smith@mydomain\fR)
1055 \fISID numeric ID\fR (for example, \fBS-1-123-456-789\fR)
1058 Files created on Linux always have POSIX owners.
1063 \fB\fBgroupquota@\fR\fIgroup\fR=\fBnone\fR\fR | \fIsize\fR
1067 Limits the amount of space consumed by the specified group. Group space consumption is identified by the \fBuserquota@\fR\fIuser\fR property.
1069 Unprivileged users can access only their own groups' space usage. The root user, or a user who has been granted the \fBgroupquota\fR privilege with \fBzfs allow\fR, can get and set all groups' quotas.
1075 \fB\fBreadonly\fR=\fBoff\fR | \fBon\fR\fR
1079 Controls whether this dataset can be modified. The default value is \fBoff\fR.
1081 This property can also be referred to by its shortened column name, \fBrdonly\fR.
1083 The values \fBon\fR and \fBoff\fR are equivalent to the \fBro\fR and \fBrw\fR mount options.
1089 \fB\fBrecordsize\fR=\fIsize\fR\fR
1093 Specifies a suggested block size for files in the file system. This property is designed solely for use with database workloads that access files in fixed-size records. \fBZFS\fR automatically tunes block sizes according to internal algorithms optimized for typical access patterns.
1095 For databases that create very large files but access them in small random chunks, these algorithms may be suboptimal. Specifying a \fBrecordsize\fR greater than or equal to the record size of the database can result in significant performance gains. Use of this property for general purpose file systems is strongly discouraged, and may adversely affect performance.
1097 Any power of two from 512B to 1MiB is valid. The default is 128KiB. Values larger than 128KiB require the pool have the \fBlarge_blocks\fR feature enabled. See \fBzpool-features\fR(5) for details on ZFS feature flags and the \fBlarge_blocks\fR feature.
1099 Changing the file system's \fBrecordsize\fR affects only files created afterward; existing files are unaffected.
1101 This property can also be referred to by its shortened column name, \fBrecsize\fR.
1107 \fB\fBredundant_metadata\fR=\fBall\fR | \fBmost\fR\fR
1111 Controls what types of metadata are stored redundantly. ZFS stores an
1112 extra copy of metadata, so that if a single block is corrupted, the
1113 amount of user data lost is limited. This extra copy is in addition to
1114 any redundancy provided at the pool level (e.g. by mirroring or RAID-Z),
1115 and is in addition to an extra copy specified by the \fBcopies\fR
1116 property (up to a total of 3 copies). For example if the pool is
1117 mirrored, \fBcopies\fR=2, and \fBredundant_metadata\fR=most, then ZFS
1118 stores 6 copies of most metadata, and 4 copies of data and some
1121 When set to \fBall\fR, ZFS stores an extra copy of all metadata. If a
1122 single on-disk block is corrupt, at worst a single block of user data
1123 (which is \fBrecordsize\fR bytes long) can be lost.
1125 When set to \fBmost\fR, ZFS stores an extra copy of most types of
1126 metadata. This can improve performance of random writes, because less
1127 metadata must be written. In practice, at worst about 100 blocks (of
1128 \fBrecordsize\fR bytes each) of user data can be lost if a single
1129 on-disk block is corrupt. The exact behavior of which metadata blocks
1130 are stored redundantly may change in future releases.
1132 The default value is \fBall\fR.
1138 \fB\fBrefquota\fR=\fBnone\fR | \fIsize\fR\fR
1142 Limits the amount of space a dataset can consume. This property enforces a hard limit on the amount of space used. This hard limit does not include space used by descendents, including file systems and snapshots.
1148 \fB\fBrefreservation\fR=\fBnone\fR | \fIsize\fR\fR
1152 The minimum amount of space guaranteed to a dataset, not including its descendents. When the amount of space used is below this value, the dataset is treated as if it were taking up the amount of space specified by \fBrefreservation\fR. The \fBrefreservation\fR reservation is accounted for in the parent datasets' space used, and counts against the parent datasets' quotas and reservations.
1154 If \fBrefreservation\fR is set, a snapshot is only allowed if there is enough free pool space outside of this reservation to accommodate the current number of \fBreferenced\fR bytes in the dataset (which are the bytes to be referenced by the snapshot). This is necessary to continue to provide the \fBrefreservation\fRguarantee to the dataset.
1156 For volumes, see also \fBvolsize\fR.
1158 This property can also be referred to by its shortened column name, \fBrefreserv\fR.
1164 \fB\fBrelatime\fR=\fBoff\fR | \fBon\fR\fR
1168 Controls the manner in which the access time is updated when \fBatime=on\fR is set. Turning this property \fBon\fR causes the access time to be updated relative to the modify or change time. Access time is only updated if the previous access time was earlier than the current modify or change time or if the existing access time hasn't been updated within the past 24 hours. The default value is \fBoff\fR.
1170 The values \fBon\fR and \fBoff\fR are equivalent to the \fBrelatime\fR and \fBnorelatime\fR mount options.
1176 \fB\fBreservation\fR=\fBnone\fR | \fIsize\fR\fR
1180 The minimum amount of space guaranteed to a dataset and its descendents. When the amount of space used is below this value, the dataset is treated as if it were taking up the amount of space specified by its reservation. Reservations are accounted for in the parent datasets' space used, and count against the parent datasets' quotas and reservations.
1182 This property can also be referred to by its shortened column name, \fBreserv\fR.
1188 \fB\fBsecondarycache\fR=\fBall\fR | \fBnone\fR | \fBmetadata\fR\fR
1192 Controls what is cached in the secondary cache (L2ARC). If this property is set to \fBall\fR, then both user data and metadata is cached. If this property is set to \fBnone\fR, then neither user data nor metadata is cached. If this property is set to \fBmetadata\fR, then only metadata is cached. The default value is \fBall\fR.
1198 \fB\fBsetuid\fR=\fBon\fR | \fBoff\fR\fR
1202 Controls whether the setuid bit is respected for the file system. The default value is \fBon\fR.
1204 The values \fBon\fR and \fBoff\fR are equivalent to the \fBsuid\fR and \fBnosuid\fR mount options.
1210 \fB\fBsharesmb\fR=\fBoff\fR | \fBon\fR
1214 Controls whether the file system is shared by using \fBSamba USERSHARES\fR, and what options are to be used. Otherwise, the file system is automatically shared and unshared with the \fBzfs share\fR and \fBzfs unshare\fR commands. If the property is set to \fBon\fR, the \fBnet\fR(8) command is invoked to create a \fBUSERSHARE\fR.
1216 Because \fBSMB\fR shares requires a resource name, a unique resource name is constructed from the dataset name. The constructed name is a copy of the dataset name except that the characters in the dataset name, which would be invalid in the resource name, are replaced with underscore (\fB_\fR) characters. Linux does not currently support additional options which might be available on Solaris.
1218 If the \fBsharesmb\fR property is set to \fBoff\fR, the file systems are unshared.
1220 In Linux, the share is created with the ACL (Access Control List) "Everyone:F" ("F" stands for "full permissions", ie. read and write permissions) and no guest access (which means Samba must be able to authenticate a real user, system passwd/shadow, LDAP or smbpasswd based) by default. This means that any additional access control (disallow specific user specific access etc) must be done on the underlaying filesystem.
1223 Example to mount a SMB filesystem shared through ZFS (share/tmp):
1224 Note that a user and his/her password \fBmust\fR be given!
1227 smbmount //127.0.0.1/share_tmp /mnt/tmp -o user=workgroup/turbo,password=obrut,uid=1000
1233 \fBMinimal /etc/samba/smb.conf configuration\fR
1236 * Samba will need to listen to 'localhost' (127.0.0.1) for the zfs utilities to communicate with Samba. This is the default behavior for most Linux distributions.
1238 * Samba must be able to authenticate a user. This can be done in a number of ways, depending on if using the system password file, LDAP or the Samba specific smbpasswd file. How to do this is outside the scope of this manual. Please refer to the smb.conf(5) manpage for more information.
1240 * See the \fBUSERSHARE\fR section of the \fBsmb.conf\fR(5) man page for all configuration options in case you need to modify any options to the share afterwards. Do note that any changes done with the 'net' command will be undone if the share is every unshared (such as at a reboot etc). In the future, ZoL will be able to set specific options directly using sharesmb=<option>.
1248 \fB\fBsharenfs\fR=\fBoff\fR | \fBon\fR | \fIopts\fR\fR
1252 Controls whether the file system is shared via \fBNFS\fR, and what options are used. A file system with a \fBsharenfs\fR property of \fBoff\fR is managed with the \fBexportfs\fR(8) command and entries in \fB/etc/exports\fR file. Otherwise, the file system is automatically shared and unshared with the \fBzfs share\fR and \fBzfs unshare\fR commands. If the property is set to \fBon\fR, the dataset is shared using the \fBexportfs\fR(8) command in the following manner (see \fBexportfs\fR(8) for the meaning of the different options):
1256 /usr/sbin/exportfs -i -o sec=sys,rw,no_subtree_check,no_root_squash,mountpoint *:<mountpoint of dataset>
1260 Otherwise, the \fBexportfs\fR(8) command is invoked with options equivalent to the contents of this property.
1262 When the \fBsharenfs\fR property is changed for a dataset, the dataset and any children inheriting the property are re-shared with the new options, only if the property was previously \fBoff\fR, or if they were shared before the property was changed. If the new property is \fBoff\fR, the file systems are unshared.
1268 \fB\fBlogbias\fR=\fBlatency\fR | \fBthroughput\fR\fR
1272 Provide a hint to ZFS about handling of synchronous requests in this dataset. If \fBlogbias\fR is set to \fBlatency\fR (the default), ZFS will use pool log devices (if configured) to handle the requests at low latency. If \fBlogbias\fR is set to \fBthroughput\fR, ZFS will not use configured pool log devices. ZFS will instead optimize synchronous operations for global pool throughput and efficient use of resources.
1278 \fB\fBsnapdev\fR=\fBhidden\fR | \fBvisible\fR\fR
1282 Controls whether the snapshots devices of zvol's are hidden or visible. The default value is \fBhidden\fR.
1284 In this context, hidden does not refer to the concept of hiding files or directories by starting their name with a "." character. Even with \fBvisible\fR, the directory is still named \fB\&.zfs\fR. Instead, \fBhidden\fR means that the directory is not returned by \fBreaddir\fR(3), so it doesn't show up in directory listings done by any program, including \fBls\fR \fB-a\fR. It is still possible to chdir(2) into the directory, so \fBcd\fR \fB\&.zfs\fR works even with \fBhidden\fR. This unusual behavior is to protect against unwanted effects from applications recursing into the special \fB\&.zfs\fR directory.
1290 \fB\fBsnapdir\fR=\fBhidden\fR | \fBvisible\fR\fR
1294 Controls whether the \fB\&.zfs\fR directory is hidden or visible in the root of the file system as discussed in the "Snapshots" section. The default value is \fBhidden\fR.
1300 \fB\fBsync\fR=\fBstandard\fR | \fBalways\fR | \fBdisabled\fR\fR
1304 Controls the behavior of synchronous requests (e.g. fsync, O_DSYNC).
1305 \fBstandard\fR is the POSIX specified behavior of ensuring all synchronous
1306 requests are written to stable storage and all devices are flushed to ensure
1307 data is not cached by device controllers (this is the default). \fBalways\fR
1308 causes every file system transaction to be written and flushed before its
1309 system call returns. This has a large performance penalty. \fBdisabled\fR
1310 disables synchronous requests. File system transactions are only committed to
1311 stable storage periodically. This option will give the highest performance.
1312 However, it is very dangerous as ZFS would be ignoring the synchronous
1313 transaction demands of applications such as databases or NFS. Administrators
1314 should only use this option when the risks are understood.
1320 \fB\fBversion\fR=\fB5\fR | \fB4\fR | \fB3\fR | \fB2\fR | \fB1\fR | \fBcurrent\fR\fR
1324 The on-disk version of this file system, which is independent of the pool version. This property can only be set to later supported versions. The value \fBcurrent\fR automatically selects the latest supported version. See the \fBzfs upgrade\fR command.
1330 \fB\fBvolsize\fR=\fIsize\fR\fR
1334 For volumes, specifies the logical size of the volume. By default, creating a volume establishes a \fBrefreservation\fR equal to the volume size plus the metadata required for a fully-written volume. (For pool version 8 or lower, a \fBreservation\fR is set instead.) Any changes to \fBvolsize\fR are reflected in an equivalent change to the \fBrefreservation\fR. The \fBvolsize\fR can only be set to a multiple of \fBvolblocksize\fR, and cannot be zero.
1336 Without the reservation, the volume could run out of space, resulting in undefined behavior or data corruption, depending on how the volume is used. These effects can also occur when the volume size is changed while it is in use (particularly when shrinking the size). Extreme care should be used when adjusting the volume size.
1338 A "sparse volume" (also known as "thin provisioning") can be created by specifying the \fB-s\fR option to the \fBzfs create -V\fR command, or by removing (or changing) the \fBrefreservation\fR after the volume has been created. A "sparse volume" is a volume where the \fBrefreservation\fR is unset or less then the volume size. Consequently, writes to a sparse volume can fail with \fBENOSPC\fR when the pool is low on space. For a sparse volume, changes to \fBvolsize\fR are not reflected in the reservation.
1344 \fB\fBvscan\fR=\fBoff\fR | \fBon\fR\fR
1348 Controls whether regular files should be scanned for viruses when a file is opened and closed. In addition to enabling this property, the virus scan service must also be enabled for virus scanning to occur. The default value is \fBoff\fR.
1350 This property is not used on Linux.
1356 \fB\fBxattr\fR=\fBon\fR | \fBoff\fR | \fBsa\fR\fR
1360 Controls whether extended attributes are enabled for this file system. Two
1361 styles of extended attributes are supported either directory based or system
1364 The default value of \fBon\fR enables directory based extended attributes.
1365 This style of xattr imposes no practical limit on either the size or number of
1366 xattrs which may be set on a file. Although under Linux the \fBgetxattr\fR(2)
1367 and \fBsetxattr\fR(2) system calls limit the maximum xattr size to 64K. This
1368 is the most compatible style of xattr and it is supported by the majority of
1369 ZFS implementations.
1371 System attribute based xattrs may be enabled by setting the value to \fBsa\fR.
1372 The key advantage of this type of xattr is improved performance. Storing
1373 xattrs as system attributes significantly decreases the amount of disk IO
1374 required. Up to 64K of xattr data may be stored per file in the space reserved
1375 for system attributes. If there is not enough space available for an xattr then
1376 it will be automatically written as a directory based xattr. System attribute
1377 based xattrs are not accessible on platforms which do not support the
1378 \fBxattr=sa\fR feature.
1380 The use of system attribute based xattrs is strongly encouraged for users of
1381 SELinux or Posix ACLs. Both of these features heavily rely of xattrs and
1382 benefit significantly from the reduced xattr access time.
1384 The values \fBon\fR and \fBoff\fR are equivalent to the \fBxattr\fR and \fBnoxattr\fR mount options.
1390 \fB\fBzoned\fR=\fBoff\fR | \fBon\fR\fR
1394 Controls whether the dataset is managed from a non-global zone. Zones are a Solaris feature and are not relevant on Linux. The default value is \fBoff\fR.
1399 The following three properties cannot be changed after the file system is created, and therefore, should be set when the file system is created. If the properties are not set with the \fBzfs create\fR or \fBzpool create\fR commands, these properties are inherited from the parent dataset. If the parent dataset lacks these properties due to having been created prior to these features being supported, the new file system will have the default values for these properties.
1403 \fB\fBcasesensitivity\fR=\fBsensitive\fR | \fBinsensitive\fR | \fBmixed\fR\fR
1407 Indicates whether the file name matching algorithm used by the file system should be case-sensitive, case-insensitive, or allow a combination of both styles of matching. The default value for the \fBcasesensitivity\fR property is \fBsensitive\fR. Traditionally, UNIX and POSIX file systems have case-sensitive file names.
1409 The \fBmixed\fR value for the \fBcasesensitivity\fR property indicates that the file system can support requests for both case-sensitive and case-insensitive matching behavior. Currently, case-insensitive matching behavior on a file system that supports mixed behavior is limited to the Solaris CIFS server product.
1415 \fB\fBnormalization\fR = \fBnone\fR | \fBformC\fR | \fBformD\fR | \fBformKC\fR | \fBformKD\fR\fR
1419 Indicates whether the file system should perform a Unicode normalization of file names whenever two file names are compared, and which normalization algorithm should be used.
1421 If this property is set to a value other than \fBnone\fR (the default), and the \fButf8only\fR property was left unspecified, the \fButf8only\fR property is automatically set to \fBon\fR. See the cautionary note in the \fButf8only\fR section before modifying \fBnormalization\fR.
1423 File names are always stored unmodified; names are normalized as part of any comparison process. Thus, \fBformC\fR and \fBformD\fR are equivalent, as are \fBformKC\fR and \fBformKD\fR. Given that, only \fBformD\fR and \fBformKD\fR make sense, as they are slightly faster because they avoid the additional canonical composition step.
1424 .\" unicode.org says it's possible to quickly detect if a string is already in a given form. Since most text (basically everything but OS X) is already in NFC, this means formC could potentially be made faster. But the additional complexity probably isn't worth the likely undetectable in practice speed improvement.
1426 The practical impact of this property is: \fBnone\fR (like traditional filesystems) allows a directory to contain two files that appear (to humans) to have the same name. The other options solve this problem, for different definitions of "the same". If you need to solve this problem and are not sure what to choose,\fBformD\fR.
1428 This property cannot be changed after the file system is created.
1434 \fB\fButf8only\fR=\fBoff\fR | \fBon\fR\fR
1438 Indicates whether the file system should reject file names that include characters that are not present in the \fBUTF-8\fR character set. If this property is explicitly set to \fBoff\fR, the \fBnormalization\fR property must either not be explicitly set or be set to \fBnone\fR. The default value for the \fButf8only\fR property is \fBoff\fR.
1440 Note that forcing the use of \fBUTF-8\fR filenames may cause pain for users. For example, extracting files from an archive will fail if the filenames within the archive are encoded in another character set.
1442 If you are thinking of setting this (to \fBon\fR), you probably want to set \fBnormalization\fR=\fBformD\fR which will set this property to \fBon\fR implicitly.
1444 This property cannot be changed after the file system is created.
1449 The \fBcasesensitivity\fR, \fBnormalization\fR, and \fButf8only\fR properties are also permissions that can be assigned to non-privileged users by using the \fBZFS\fR delegated administration feature.
1455 \fB\fBcontext\fR=\fBnone\fR | \fISELinux_User:SElinux_Role:Selinux_Type:Sensitivity_Level\fR\fR
1459 This flag sets the SELinux context for all files in the filesystem under the mountpoint for that filesystem. See \fBselinux\fR(8) for more information.
1465 \fB\fBfscontext\fR=\fBnone\fR | \fISELinux_User:SElinux_Role:Selinux_Type:Sensitivity_Level\fR\fR
1469 This flag sets the SELinux context for the filesystem being mounted. See \fBselinux\fR(8) for more information.
1475 \fB\fBdefcontext\fR=\fBnone\fR | \fISELinux_User:SElinux_Role:Selinux_Type:Sensitivity_Level\fR\fR
1479 This flag sets the SELinux context for unlabeled files. See \fBselinux\fR(8) for more information.
1485 \fB\fBrootcontext\fR=\fBnone\fR | \fISELinux_User:SElinux_Role:Selinux_Type:Sensitivity_Level\fR\fR
1489 This flag sets the SELinux context for the root inode of the filesystem. See \fBselinux\fR(8) for more information.
1495 \fB\fBoverlay\fR=\fBoff\fR | \fBon\fR\fR
1499 Allow mounting on a busy directory or a directory which already contains files/directories. This is the default mount behavior for Linux filesystems. However, for consistency with ZFS on other platforms overlay mounts are disabled by default. Set \fBoverlay=on\fR to enable overlay mounts.
1502 .SS "Temporary Mount Point Properties"
1504 When a file system is mounted, either through \fBmount\fR(8) for legacy mounts or the \fBzfs mount\fR command for normal file systems, its mount options are set according to its properties. The correlation between properties and mount options is as follows:
1508 PROPERTY MOUNT OPTION
1510 canmount auto/noauto
1511 devices devices/nodevices
1514 relatime relatime/norelatime
1517 nbmand nbmand/nonbmand (Solaris)
1524 In addition, these options can be set on a per-mount basis using the \fB-o\fR option, without affecting the property that is stored on disk. The values specified on the command line override the values stored in the dataset. The \fB-nosuid\fR option is an alias for \fBnodevices,nosetuid\fR. These properties are reported as "temporary" by the \fBzfs get\fR command. If the properties are changed while the dataset is mounted, the new setting overrides any temporary settings.
1525 .SS "User Properties"
1527 In addition to the standard native properties, \fBZFS\fR supports arbitrary user properties. User properties have no effect on \fBZFS\fR behavior, but applications or administrators can use them to annotate datasets (file systems, volumes, and snapshots). Unlike native properties, user properties are editable on snapshots.
1530 User property names must contain a colon (\fB:\fR) character to distinguish them from native properties. They may contain lowercase letters, numbers, and the following punctuation characters: colon (\fB:\fR), dash (\fB-\fR), period (\fB\&.\fR), and underscore (\fB_\fR). The expected convention is that the property name is divided into two portions such as \fImodule\fR\fB:\fR\fIproperty\fR, but this namespace is not enforced by \fBZFS\fR. User property names can be at most 256 characters, and cannot begin with a dash (\fB-\fR).
1533 When making programmatic use of user properties, it is strongly suggested to use a reversed \fBDNS\fR domain name for the \fImodule\fR component of property names to reduce the chance that two independently-developed packages use the same property name for different purposes. For example, property names beginning with \fBcom.sun\fR. are reserved for definition by Oracle Corporation (which acquired Sun Microsystems).
1536 The values of user properties are arbitrary strings, are always inherited, and are never validated. All of the commands that operate on properties (\fBzfs list\fR, \fBzfs get\fR, \fBzfs set\fR, and so forth) can be used to manipulate both native properties and user properties. Use the \fBzfs inherit\fR command to clear a user property. If the property is not defined in any parent dataset, it is removed entirely. Property values are limited to 1024 characters.
1537 .SS "ZFS Volumes as Swap"
1539 \fBZFS\fR volumes may be used as Linux swap devices. After creating the volume
1540 with the \fBzfs create\fR command set up and enable the swap area using the
1541 \fBmkswap\fR(8) and \fBswapon\fR(8) commands. Do not swap to a file on a
1542 \fBZFS\fR file system. A \fBZFS\fR swap file configuration is not supported.
1545 All subcommands that modify state are logged persistently to the pool in their original form. The log can be viewed with \fBzpool history\fR.
1553 Displays a help message.
1559 \fB\fBzfs create\fR [\fB-p\fR] [\fB-o\fR \fIproperty\fR=\fIvalue\fR] ... \fIfilesystem\fR\fR
1563 Creates a new \fBZFS\fR file system. The file system is automatically mounted according to the \fBmountpoint\fR and \fBcanmount\fR properties.
1571 Creates all the non-existing parent datasets. Datasets created in this manner inherit their properties; any property specified on the command line using the \fB-o\fR option applies only to the final child file system. If the target filesystem already exists, the operation completes successfully and no properties are changed.
1577 \fB\fB-o\fR \fIproperty\fR=\fIvalue\fR\fR
1581 Sets the specified property as if the command \fBzfs set\fR \fIproperty\fR=\fIvalue\fR was invoked at the same time the dataset was created. Any editable \fBZFS\fR property can also be set at creation time. Multiple \fB-o\fR options can be specified. An error results if the same property is specified in multiple \fB-o\fR options.
1589 \fB\fBzfs create\fR [\fB-ps\fR] [\fB-b\fR \fIblocksize\fR] [\fB-o\fR \fIproperty\fR=\fIvalue\fR] ... \fB-V\fR \fIsize\fR \fIvolume\fR\fR
1593 Creates a volume of the given size. The volume is exported as a block device in \fB/dev/zvol/\fR\fIpath\fR, where \fIpath\fR is the name of the volume in the \fBZFS\fR namespace. The size represents the logical size as exported by the device. By default, a \fBrefreservation\fR is created.
1595 \fIsize\fR is automatically rounded up to the nearest 128KiB to ensure that the volume has an integral number of blocks regardless of \fIblocksize\fR.
1603 Creates all the non-existing parent datasets as file systems. Datasets created in this manner inherit their properties; any property specified on the command line using the \fB-o\fR option applies only to the final child volume. If the target volume already exists, the operation completes successfully and no properties are changed.
1613 Creates a sparse volume by omitting the automatic creation of a \fBrefreservation\fR. See \fBvolsize\fR in the Native Properties section for more information about sparse volumes. If this option is specified in conjunction with \fB-o\fR \fBrefreservation\fR, the \fBrefreservation\fR will be honored; this allows for a partial reservation on a sparse volume.
1619 \fB\fB-o\fR \fIproperty\fR=\fIvalue\fR\fR
1623 Sets the specified property as if the \fBzfs set\fR \fIproperty\fR=\fIvalue\fR command was invoked at the same time the dataset was created. Any editable \fBZFS\fR property can also be set at creation time. Multiple \fB-o\fR options can be specified. An error results if the same property is specified in multiple \fB-o\fR options.
1625 If \fB-o\fR \fBvolsize\fR is provided, the resulting behavior is undefined; it conflicts with the -V option, which is required in this mode.
1631 \fB\fB-b\fR \fIblocksize\fR\fR
1635 Equivalent to \fB-o\fR \fBvolblocksize\fR=\fIblocksize\fR. If this option is specified in conjunction with \fB-o\fR \fBvolblocksize\fR, the resulting behavior is undefined.
1643 \fBzfs destroy\fR [\fB-fnpRrv\fR] \fIfilesystem\fR|\fIvolume\fR
1647 Destroys the given dataset. By default, the command unshares any file systems that are currently shared, unmounts any file systems that are currently mounted, and refuses to destroy a dataset that has active dependents (children or clones).
1655 Recursively destroy all children.
1665 Recursively destroy all dependents, including cloned file systems outside the target hierarchy.
1675 Force an unmount of any file systems using the \fBzfs unmount -f\fR command. This option has no effect on non-file systems or unmounted file systems.
1685 Do a dry-run ("No-op") deletion. No data will be deleted. This is
1686 useful in conjunction with the \fB-v\fR or \fB-p\fR flags to determine what
1687 data would be deleted.
1697 Print machine-parsable verbose information about the deleted data.
1707 Print verbose information about the deleted data.
1711 Extreme care should be taken when applying either the \fB-r\fR or the \fB-R\fR options, as they can destroy large portions of a pool.
1717 \fBzfs destroy\fR [\fB-dnpRrv\fR] \fIfilesystem\fR|\fIvolume\fR@\fIsnap\fR[%\fIsnap\fR][,...]
1721 The specified snapshots are destroyed immediately if they have no clones and the user-initiated reference count is zero (i.e. there are no holds set with \fBzfs hold\fR). If these conditions are not met, this command returns an error, unless \fB-d\fR is supplied.
1723 An inclusive range of snapshots may be specified by separating the
1724 first and last snapshots with a percent sign.
1725 The first and/or last snapshots may be left blank, in which case the
1726 filesystem's oldest or newest snapshot will be implied.
1729 (or ranges of snapshots) of the same filesystem or volume may be specified
1730 in a comma-separated list of snapshots.
1731 Only the snapshot's short name (the
1732 part after the \fB@\fR) should be specified when using a range or
1733 comma-separated list to identify multiple snapshots.
1741 If a snapshot does not qualify for immediate destruction, rather than returning an error, it is marked for deferred destruction. In this state, it exists as a usable, visible snapshot until both of the preconditions listed above are met, at which point it is destroyed.
1751 Destroy (or mark for deferred destruction) all snapshots with this name in descendent file systems.
1761 Recursively destroy all clones of these snapshots, including the clones,
1762 snapshots, and children. If this flag is specified, the \fB-d\fR flag will
1773 Do a dry-run ("No-op") deletion. No data will be deleted. This is
1774 useful in conjunction with the \fB-v\fR or \fB-p\fR flags to determine what
1775 data would be deleted.
1785 Print machine-parsable verbose information about the deleted data.
1795 Print verbose information about the deleted data.
1799 Extreme care should be taken when applying either the \fB-r\fR or the \fB-R\fR
1800 options, as they can destroy large portions of a pool and cause unexpected
1801 behavior for mounted file systems in use.
1809 \fBzfs destroy\fR \fIfilesystem\fR|\fIvolume\fR#\fIbookmark\fR
1813 The given bookmark is destroyed.
1820 \fB\fBzfs snapshot\fR [\fB-r\fR] [\fB-o\fR \fIproperty\fR=\fIvalue\fR] ... \fIfilesystem@snapname\fR|\fIvolume@snapname\fR\fR ...
1824 Creates snapshots with the given names. All previous modifications by successful system calls to the file system are part of the snapshots. Snapshots are taken atomically, so that all snapshots correspond to the same moment in time. See the "Snapshots" section for details.
1832 Recursively create snapshots of all descendent datasets.
1838 \fB\fB-o\fR \fIproperty\fR=\fIvalue\fR\fR
1842 Sets the specified property; see \fBzfs set\fR for details.
1850 \fB\fBzfs rollback\fR [\fB-rRf\fR] \fIsnapshot\fR\fR
1854 Roll back the given dataset to a previous snapshot. When a dataset is rolled back, all data that has changed since the snapshot is discarded, and the dataset reverts to the state at the time of the snapshot. By default, the command refuses to roll back to a snapshot other than the most recent one. In order to do so, all intermediate snapshots and bookmarks must be destroyed by specifying the \fB-r\fR option.
1856 The \fB-rR\fR options do not recursively destroy the child snapshots of a recursive snapshot. Only direct snapshots of the specified filesystem are destroyed by either of these options. To completely roll back a recursive snapshot, you must rollback the individual child snapshots.
1864 Destroy any snapshots and bookmarks more recent than the one specified.
1874 Recursively destroy any more recent snapshots and bookmarks, as well as any clones of those snapshots.
1884 Used with the \fB-R\fR option to force an unmount (see \fBzfs unmount -f\fR) of any clone file systems that are to be destroyed.
1892 \fB\fBzfs clone\fR [\fB-p\fR] [\fB-o\fR \fIproperty\fR=\fIvalue\fR] ... \fIsnapshot\fR \fIfilesystem\fR|\fIvolume\fR\fR
1896 Creates a clone of the given snapshot. See the "Clones" section for details. The target dataset can be located anywhere in the \fBZFS\fR hierarchy, and is created as the same type as the original.
1904 Creates all the non-existing parent datasets; see \fBzfs create\fR for details.
1910 \fB\fB-o\fR \fIproperty\fR=\fIvalue\fR\fR
1914 Sets the specified property; see \fBzfs set\fR for details.
1922 \fB\fBzfs promote\fR \fIclone-filesystem\fR\fR
1926 Promotes a clone file system to no longer be dependent on its "origin" snapshot. This makes it possible to destroy the file system that the clone was created from. The clone parent-child dependency relationship is reversed, so that the origin file system becomes a clone of the specified file system.
1928 The snapshot that was cloned, and any snapshots previous to this snapshot, are now owned by the promoted clone. The space they use moves from the origin file system to the promoted clone, so enough space must be available to accommodate these snapshots. No new space is consumed by this operation, but the space accounting is adjusted. The promoted clone must not have any conflicting snapshot names of its own. The \fBzfs rename\fR command can be used to rename any conflicting snapshots.
1934 \fB\fBzfs rename\fR [\fB-f\fR] \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR\fR
1938 \fB\fBzfs rename\fR [\fB-fp\fR] \fIfilesystem\fR|\fIvolume\fR \fIfilesystem\fR|\fIvolume\fR\fR
1942 Renames the given dataset. The new target can be located anywhere in the \fBZFS\fR hierarchy, with the exception of snapshots. Snapshots can only be renamed within the parent file system or volume. When renaming a snapshot, the parent file system of the snapshot does not need to be specified as part of the second argument. Renamed file systems can inherit new mount points, in which case they are unmounted and remounted at the new mount point.
1950 Creates all the nonexistent parent datasets; see \fBzfs create\fR for details.
1960 Force unmount any filesystems that need to be unmounted in the process.
1968 \fB\fBzfs rename\fR \fB-r\fR \fIsnapshot\fR \fIsnapshot\fR\fR
1972 Recursively rename the snapshots of all descendent datasets. Snapshots are the only dataset that can be renamed recursively.
1978 \fB\fBzfs\fR \fBlist\fR [\fB-r\fR|\fB-d\fR \fIdepth\fR] [\fB-Hp\fR] [\fB-o\fR \fIproperty\fR[,\fI\&...\fR]] [ \fB-t\fR \fItype\fR[,\fI\&...\fR]] [ \fB-s\fR \fIproperty\fR ] ... [ \fB-S\fR \fIproperty\fR ] ... [\fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR|\fImountpoint\fR] ...\fR
1982 Lists the property information for the given datasets in tabular form. If a mount point is specified, it can be an absolute pathname or a relative pathname starting with "./" (e.g. \fBzfs list ./\fR). By default, all file systems and volumes are displayed. Snapshots are displayed if the pool's \fBlistsnapshots\fR property is \fBon\fR (the default is \fBoff\fR). When listing hundreds or thousands of snapshots performance can be improved by restricting the output to only the name. In that case, it is recommended to use \fB-o name -s name\fR. The following fields are displayed by default: \fBname, used, available, referenced, mountpoint\fR
1990 Used for scripting mode. Do not print headers and separate fields by a single tab instead of arbitrary white space.
1999 Display numbers in parsable (exact) values.
2009 Recursively display any children of the dataset on the command line.
2015 \fB\fB-d\fR \fIdepth\fR\fR
2019 Recursively display any children of the dataset, limiting the recursion to \fIdepth\fR. A depth of \fB1\fR will display only the dataset and its direct children.
2025 \fB\fB-o\fR \fIproperty\fR\fR
2029 A comma-separated list of properties to display. The property must be:
2034 One of the properties described in the "Native Properties" section
2046 The value \fBname\fR to display the dataset name
2052 The value \fBspace\fR to display space usage properties on file systems and volumes. This is a shortcut for specifying \fB-o name,avail,used,usedsnap,usedds,usedrefreserv,usedchild\fR \fB-t filesystem,volume\fR syntax.
2059 \fB\fB-s\fR \fIproperty\fR\fR
2063 A property for sorting the output by column in ascending order based on the value of the property. The property must be one of the properties described in the "Properties" section, or the special value \fBname\fR to sort by the dataset name. Multiple properties can be specified at one time using multiple \fB-s\fR property options. Multiple \fB-s\fR options are evaluated from left to right in decreasing order of importance.
2065 The following is a list of sorting criteria:
2070 Numeric types sort in numeric order.
2076 String types sort in alphabetical order.
2082 Types inappropriate for a row sort that row to the literal bottom, regardless of the specified ordering.
2088 If no sorting options are specified the existing behavior of \fBzfs list\fR is preserved.
2095 \fB\fB-S\fR \fIproperty\fR\fR
2099 Same as the \fB-s\fR option, but sorts by property in descending order.
2105 \fB\fB-t\fR \fItype\fR\fR
2109 A comma-separated list of types to display, where \fItype\fR is one of \fBfilesystem\fR, \fBsnapshot\fR, \fBsnap\fR, \fBvolume\fR, \fBbookmark\fR, or \fBall\fR. For example, specifying \fB-t snapshot\fR displays only snapshots.
2117 \fB\fBzfs set\fR \fIproperty\fR=\fIvalue\fR[ \fIproperty\fR=\fIvalue\fR]...
2118 \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR ...\fR
2122 Sets the property or list of properties to the given value(s) for each dataset.
2123 Only some properties can be edited. See the "Properties" section for more
2124 information on which properties can be set and acceptable values. User properties
2125 can be set on snapshots. For more information, see the "User Properties" section.
2130 \fB\fBzfs get\fR [\fB-r\fR|\fB-d\fR \fIdepth\fR] [\fB-Hp\fR] [\fB-o\fR \fIfield\fR[,...] [\fB-t\fR \fItype\fR[,...]] [\fB-s\fR \fIsource\fR[,...] "\fIall\fR" | \fIproperty\fR[,...] \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR ...\fR
2134 Displays properties for the given datasets. If no datasets are specified, then the command displays properties for all datasets on the system. For each property, the following columns are displayed:
2139 property Property name
2140 value Property value
2141 source Property source. Can either be local, default,
2142 temporary, inherited, received, or none (-).
2147 All columns are displayed by default, though this can be controlled by using the \fB-o\fR option. This command takes a comma-separated list of properties as described in the "Native Properties" and "User Properties" sections.
2149 The special value \fBall\fR can be used to display all properties that apply to the given dataset's type (filesystem, volume snapshot, or bookmark).
2157 Recursively display properties for any children.
2163 \fB\fB-d\fR \fIdepth\fR\fR
2167 Recursively display any children of the dataset, limiting the recursion to \fIdepth\fR. A depth of \fB1\fR will display only the dataset and its direct children.
2177 Display output in a form more easily parsed by scripts. Any headers are omitted, and fields are explicitly separated by a single tab instead of an arbitrary amount of space.
2183 \fB\fB-o\fR \fIfield\fR\fR
2187 A comma-separated list of columns to display. \fBname,property,value,source\fR is the default value.
2193 \fB\fB-s\fR \fIsource\fR\fR
2197 A comma-separated list of sources to display. Those properties coming from a source other than those in this list are ignored. Each source must be one of the following: \fBlocal,default,inherited,received,temporary,none\fR. The default value is all sources.
2207 Display numbers in parsable (exact) values.
2215 \fB\fBzfs inherit\fR [\fB-rS\fR] \fIproperty\fR \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR ...\fR
2219 Clears the specified property, causing it to be inherited from an ancestor, restored to default if no ancestor has the property set, or with the \fB-S\fR option reverted to the received value if one exists. See the "Properties" section for a listing of default values, and details on which properties can be inherited.
2227 Recursively inherit the given property for all children.
2236 Revert the property to the received value if one exists; otherwise operate as
2237 if the \fB-S\fR option was not specified.
2245 \fB\fBzfs upgrade\fR
2249 Displays a list of file systems that are not the most recent version.
2255 \fB\fBzfs upgrade\fR \fB-v\fR\fR
2259 Displays a list of file system versions.
2266 \fB\fBzfs upgrade\fR [\fB-r\fR] [\fB-V\fR \fIversion\fR] [\fB-a\fR | \fIfilesystem\fR]\fR
2270 Upgrades file systems to a new on-disk version. Once this is done, the file systems will no longer be accessible on systems running older versions of the software. \fBzfs send\fR streams generated from new snapshots of these file systems cannot be accessed on systems running older versions of the software.
2272 In general, the file system version is independent of the pool version. See \fBzpool\fR(8) for information on the \fBzpool upgrade\fR command.
2274 In some cases, the file system version and the pool version are interrelated and the pool version must be upgraded before the file system version can be upgraded.
2282 Upgrades all file systems on all imported pools.
2288 \fB\fIfilesystem\fR\fR
2292 Upgrades the specified file system.
2302 Upgrades the specified file system and all descendent file systems
2308 \fB\fB-V\fR \fIversion\fR\fR
2312 Upgrades to the specified \fIversion\fR. If the \fB-V\fR flag is not specified, this command upgrades to the most recent version. This option can only be used to increase the version number, and only up to the most recent version supported by this software.
2320 \fBzfs\fR \fBuserspace\fR [\fB-Hinp\fR] [\fB-o\fR \fIfield\fR[,...]]
2321 [\fB-s\fR \fIfield\fR] ...
2322 [\fB-S\fR \fIfield\fR] ...
2323 [\fB-t\fR \fItype\fR[,...]] \fIfilesystem\fR|\fIsnapshot\fR
2327 Displays space consumed by, and quotas on, each user in the specified
2328 filesystem or snapshot. This corresponds to the \fBuserused@\fR\fIuser\fR and
2329 \fBuserquota@\fR\fIuser\fR properties.
2337 Print numeric ID instead of user/group name.
2347 Display output in a form more easily parsed by scripts. Any headers are omitted, and fields are explicitly separated by a single tab instead of an arbitrary amount of space.
2357 Use exact (parsable) numeric output.
2363 \fB\fB-o\fR \fIfield\fR[,...]\fR
2367 Display only the specified fields from the following
2368 set: \fBtype, name, used, quota\fR. The default is to display all fields.
2374 \fB\fB-s\fR \fIfield\fR\fR
2378 Sort output by this field. The \fIs\fR and \fIS\fR flags may be specified
2379 multiple times to sort first by one field, then by another. The default is
2380 \fB-s type\fR \fB-s name\fR.
2386 \fB\fB-S\fR \fIfield\fR\fR
2390 Sort by this field in reverse order. See \fB-s\fR.
2396 \fB\fB-t\fR \fItype\fR[,...]\fR
2400 Print only the specified types from the following
2401 set: \fBall, posixuser, smbuser, posixgroup, smbgroup\fR. The default
2402 is \fB-t posixuser,smbuser\fR. The default can be changed to include group
2413 Translate SID to POSIX ID. The POSIX ID may be ephemeral if no mapping exists.
2414 Normal POSIX interfaces (for example, \fBstat\fR(2), \fBls\fR(1) \fB-l\fR) perform
2415 this translation, so the \fB-i\fR option allows the output from \fBzfs
2416 userspace\fR to be compared directly with those utilities. However, \fB-i\fR
2417 may lead to confusion if some files were created by an SMB user before a
2418 SMB-to-POSIX name mapping was established. In such a case, some files will be owned
2419 by the SMB entity and some by the POSIX entity. However, the \fB-i\fR option
2420 will report that the POSIX entity has the total usage and quota for both.
2422 This option is not useful on Linux.
2430 \fBzfs\fR \fBgroupspace\fR [\fB-Hinp\fR] [\fB-o\fR \fIfield\fR[,...]]
2431 [\fB-s\fR \fIfield\fR] ...
2432 [\fB-S\fR \fIfield\fR] ...
2433 [\fB-t\fR \fItype\fR[,...]] \fIfilesystem\fR|\fIsnapshot\fR
2437 Displays space consumed by, and quotas on, each group in the specified
2438 filesystem or snapshot. This subcommand is identical to \fBzfs userspace\fR,
2439 except that the default types to display are \fB-t posixgroup,smbgroup\fR.
2445 \fB\fBzfs mount\fR\fR
2449 Displays all \fBZFS\fR file systems currently mounted.
2455 \fB\fBzfs mount\fR [\fB-vO\fR] [\fB-o\fR \fIoptions\fR] \fB-a\fR | \fIfilesystem\fR\fR
2459 Mounts \fBZFS\fR file systems. This is invoked automatically as part of the boot process.
2463 \fB\fB-o\fR \fIoptions\fR\fR
2467 An optional, comma-separated list of mount options to use temporarily for the
2468 duration of the mount. See the "Temporary Mount Point Properties" section for
2479 Allow mounting the filesystem even if the target directory is not empty.
2481 On Solaris, the behavior of \fBzfs mount\fR matches \fBmount\fR and \fBzfs mount -O\fR matches \fBmount -O\fR. See \fBmount\fR(1M).
2483 On Linux, this is the default for \fBmount\fR(8). In other words, \fBzfs mount -O\fR matches \fBmount\fR and there is no \fBmount\fR equivalent to a plain \fBzfs mount\fR.
2493 Report mount progress. This is intended for use with \fBzfs mount -a\fR on a system with a significant number of filesystems.
2503 Mount all available \fBZFS\fR file systems. Invoked automatically as part of
2510 \fB\fIfilesystem\fR\fR
2514 Mount the specified filesystem.
2522 \fB\fBzfs unmount\fR [\fB-f\fR] \fB-a\fR | \fIfilesystem\fR|\fImountpoint\fR\fR
2526 Unmounts currently mounted \fBZFS\fR file systems. Invoked automatically as part of the shutdown process.
2534 Forcefully unmount the file system, even if it is currently in use.
2544 Unmount all available \fBZFS\fR file systems. Invoked automatically as part of the shutdown process.
2550 \fIfilesystem\fR|\fImountpoint\fR
2554 Unmount the specified filesystem. The command can also be given a path to a \fBZFS\fR file system mount point on the system.
2562 \fB\fBzfs share\fR \fB-a\fR | \fIfilesystem\fR\fR
2566 Shares available \fBZFS\fR file systems.
2574 Share all available \fBZFS\fR file systems. Invoked automatically as part of the boot process.
2580 \fB\fIfilesystem\fR\fR
2584 Share the specified filesystem according to the \fBsharenfs\fR and \fBsharesmb\fR properties. File systems are shared when the \fBsharenfs\fR or \fBsharesmb\fR property is set.
2592 \fB\fBzfs unshare\fR \fB-a\fR | \fIfilesystem\fR|\fImountpoint\fR\fR
2596 Unshares currently shared \fBZFS\fR file systems. This is invoked automatically as part of the shutdown process.
2604 Unshare all available \fBZFS\fR file systems. Invoked automatically as part of the boot process.
2610 \fB\fIfilesystem\fR|\fImountpoint\fR\fR
2614 Unshare the specified filesystem. The command can also be given a path to a \fBZFS\fR file system shared on the system.
2622 \fB\fBzfs bookmark\fR \fIsnapshot\fR \fIbookmark\fR\fR
2626 Creates a bookmark of the given snapshot. Bookmarks mark the point in time
2627 when the snapshot was created, and can be used as the incremental source for
2628 a \fBzfs send\fR command.
2630 This feature must be enabled to be used.
2631 See \fBzpool-features\fR(5) for details on ZFS feature flags and the
2632 \fBbookmarks\fR feature.
2640 \fBzfs send\fR [\fB-DnPpRveL\fR] [\fB-\fR[\fBiI\fR] \fIsnapshot\fR] \fIsnapshot\fR
2644 Creates a stream representation of the (second, if \fB-i\fR is specified) \fIsnapshot\fR, which is written to standard output. The output can be redirected to a file or to a pipe (for example, using \fBssh\fR(1) to send it to a different system with \fBzfs receive\fR). By default, a full stream is generated; specifying \fB-i\fR or \fB-I\fR changes this behavior.
2648 \fB\fB-i\fR \fIsnapshot\fR\fR
2652 Generate an incremental stream from the first \fIsnapshot\fR (the incremental source) to the second \fIsnapshot\fR (the incremental target). The incremental source can be specified as the last component of the snapshot name (the \fB@\fR character and following) and it is assumed to be from the same file system as the incremental target.
2654 If the destination is a clone, the source may be the origin snapshot, which must be fully specified (for example, \fBpool/fs@origin\fR, not just \fB@origin\fR).
2660 \fB\fB-I\fR \fIsnapshot\fR\fR
2664 Generate a stream package that sends all intermediary snapshots from the first snapshot to the second snapshot. For example, \fB-I @a fs@d\fR is similar to \fB-i @a fs@b; -i @b fs@c; -i @c fs@d\fR. The incremental source may be specified as with the \fB-i\fR option.
2674 Generate a replication stream package, which will replicate the specified filesystem, and all descendent file systems, up to the named snapshot. When received, all properties, snapshots, descendent file systems, and clones are preserved.
2676 If the \fB-i\fR or \fB-I\fR flags are used in conjunction with the \fB-R\fR flag, an incremental replication stream is generated. The current values of properties, and current snapshot and file system names are set when the stream is received. If the \fB-F\fR flag is specified when this stream is received, snapshots and file systems that do not exist on the sending side are destroyed.
2686 Generate a deduplicated stream. Blocks which would have been sent multiple times in the send stream will only be sent once. The receiving system must also support this feature to receive a deduplicated stream. This flag can be used regardless of the dataset's dedup property, but performance will be much better if the filesystem uses a dedup-capable checksum (eg. sha256).
2696 Generate a stream which may contain blocks larger than 128KiB. This flag
2697 has no effect if the \fBlarge_blocks\fR pool feature is disabled, or if
2698 the \fRrecordsize\fR property of this filesystem has never been set above
2699 128KiB. The receiving system must have the \fBlarge_blocks\fR pool feature
2700 enabled as well. See \fBzpool-features\fR(5) for details on ZFS feature
2701 flags and the \fBlarge_blocks\fR feature.
2711 Generate a more compact stream by using WRITE_EMBEDDED records for blocks
2712 which are stored more compactly on disk by the \fBembedded_data\fR pool
2713 feature. This flag has no effect if the \fBembedded_data\fR feature is
2714 disabled. The receiving system must have the \fBembedded_data\fR feature
2715 enabled. If the \fBlz4_compress\fR feature is active on the sending system,
2716 then the receiving system must have that feature enabled as well. See
2717 \fBzpool-features\fR(5) for details on ZFS feature flags and the
2718 \fBembedded_data\fR feature.
2728 Include the dataset's properties in the stream. This flag is implicit when -R is specified. The receiving system must also support this feature.
2738 Do a dry-run ("No-op") send. Do not generate any actual send data. This is
2739 useful in conjunction with the \fB-v\fR or \fB-P\fR flags to determine what
2740 data will be sent. In this case, the verbose output will be written to
2741 standard output (contrast with a non-dry-run, where the stream is written
2742 to standard output and the verbose output goes to standard error).
2752 Print machine-parsable verbose information about the stream package generated.
2762 Print verbose information about the stream package generated. This information
2763 includes a per-second report of how much data has been sent.
2766 The format of the stream is committed. You will be able to receive your streams on future versions of \fBZFS\fR.
2773 \fBzfs send\fR [\fB-eL\fR] [\fB-i\fR \fIsnapshot\fR|\fIbookmark\fR] \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR
2777 Generate a send stream, which may be of a filesystem, and may be
2778 incremental from a bookmark. If the destination is a filesystem or volume,
2779 the pool must be read-only, or the filesystem must not be mounted. When the
2780 stream generated from a filesystem or volume is received, the default snapshot
2781 name will be "--head--".
2786 \fB-i\fR \fIsnapshot\fR|\fIbookmark\fR
2790 Generate an incremental send stream. The incremental source must be an earlier
2791 snapshot in the destination's history. It will commonly be an earlier
2792 snapshot in the destination's filesystem, in which case it can be
2793 specified as the last component of the name (the \fB#\fR or \fB@\fR character
2796 If the incremental target is a clone, the incremental source can
2797 be the origin snapshot, or an earlier snapshot in the origin's filesystem,
2798 or the origin's origin, etc.
2808 Generate a stream which may contain blocks larger than 128KiB. This flag
2809 has no effect if the \fBlarge_blocks\fR pool feature is disabled, or if
2810 the \fRrecordsize\fR property of this filesystem has never been set above
2811 128KiB. The receiving system must have the \fBlarge_blocks\fR pool feature
2812 enabled as well. See \fBzpool-features\fR(5) for details on ZFS feature
2813 flags and the \fBlarge_blocks\fR feature.
2823 Generate a more compact stream by using WRITE_EMBEDDED records for blocks
2824 which are stored more compactly on disk by the \fBembedded_data\fR pool
2825 feature. This flag has no effect if the \fBembedded_data\fR feature is
2826 disabled. The receiving system must have the \fBembedded_data\fR feature
2827 enabled. If the \fBlz4_compress\fR feature is active on the sending system,
2828 then the receiving system must have that feature enabled as well. See
2829 \fBzpool-features\fR(5) for details on ZFS feature flags and the
2830 \fBembedded_data\fR feature.
2837 \fB\fBzfs receive\fR [\fB-vnFu\fR] [\fB-o origin\fR=\fIsnapshot\fR] \fIfilesystem\fR|\fIvolume\fR|\fIsnapshot\fR\fR
2841 \fB\fBzfs receive\fR [\fB-vnFu\fR] [\fB-d\fR|\fB-e\fR] [\fB-o origin\fR=\fIsnapshot\fR] \fIfilesystem\fR\fR
2845 Creates a snapshot whose contents are as specified in the stream provided on standard input. If a full stream is received, then a new file system is created as well. Streams are created using the \fBzfs send\fR subcommand, which by default creates a full stream. \fBzfs recv\fR can be used as an alias for \fBzfs receive\fR.
2847 If an incremental stream is received, then the destination file system must already exist, and its most recent snapshot must match the incremental stream's source. For \fBzvols\fR, the destination device link is destroyed and recreated, which means the \fBzvol\fR cannot be accessed during the \fBreceive\fR operation.
2849 When a snapshot replication package stream that is generated by using the \fBzfs send\fR \fB-R\fR command is received, any snapshots that do not exist on the sending location are destroyed by using the \fBzfs destroy\fR \fB-d\fR command.
2851 The name of the snapshot (and file system, if a full stream is received) that this subcommand creates depends on the argument type and the use of the \fB-d\fR or \fB-e\fR options.
2853 If the argument is a snapshot name, the specified \fIsnapshot\fR is created. If the argument is a file system or volume name, a snapshot with the same name as the sent snapshot is created within the specified \fIfilesystem\fR or \fIvolume\fR. If neither of the \fB-d\fR or \fB-e\fR options are specified, the provided target snapshot name is used exactly as provided.
2855 The \fB-d\fR and \fB-e\fR options cause the file system name of the target snapshot to be determined by appending a portion of the sent snapshot's name to the specified target \fIfilesystem\fR. If the \fB-d\fR option is specified, all but the first element of the sent snapshot's file system path (usually the pool name) is used and any required intermediate file systems within the specified one are created. If the \fB-e\fR option is specified, then only the last element of the sent snapshot's file system name (i.e. the name of the source file system itself) is used as the target file system name.
2863 Discard the first element of the sent snapshot's file system name, using the remaining elements to determine the name of the target file system for the new snapshot as described in the paragraph above.
2873 Discard all but the last element of the sent snapshot's file system name, using that element to determine the name of the target file system for the new snapshot as described in the paragraph above.
2883 Do not mount the file system that is associated with the received stream.
2893 Print verbose information about the stream and the time required to perform the receive operation.
2903 Do not actually receive the stream. This can be useful in conjunction with the \fB-v\fR option to verify the name the receive operation would use.
2909 \fB\fB-o\fR \fBorigin\fR=\fIsnapshot\fR
2913 Forces the stream to be received as a clone of the given snapshot. This is only valid if the stream is an incremental stream whose source is the same as the provided origin.
2923 Force a rollback of the file system to the most recent snapshot before performing the receive operation. If receiving an incremental replication stream (for example, one generated by \fBzfs send -R -[iI]\fR), destroy snapshots and file systems that do not exist on the sending side.
2931 \fB\fBzfs allow\fR \fIfilesystem\fR | \fIvolume\fR\fR
2935 Displays permissions that have been delegated on the specified filesystem or volume. See the other forms of \fBzfs allow\fR for more information.
2941 \fB\fBzfs allow\fR [\fB-ldug\fR] "\fIeveryone\fR"|\fIuser\fR|\fIgroup\fR[,...] \fIperm\fR|@\fIsetname\fR[,...] \fIfilesystem\fR| \fIvolume\fR\fR
2945 \fB\fBzfs allow\fR [\fB-ld\fR] \fB-e\fR \fIperm\fR|@\fIsetname\fR[,...] \fIfilesystem\fR | \fIvolume\fR\fR
2949 Delegates \fBZFS\fR administration permission for the file systems to non-privileged users.
2953 \fB[\fB-ug\fR] "\fIeveryone\fR"|\fIuser\fR|\fIgroup\fR[,...]\fR
2957 Specifies to whom the permissions are delegated. Multiple entities can be specified as a comma-separated list. If neither of the \fB-ug\fR options are specified, then the argument is interpreted preferentially as the keyword "everyone", then as a user name, and lastly as a group name. To specify a user or group named "everyone", use the \fB-u\fR or \fB-g\fR options. To specify a group with the same name as a user, use the \fB-g\fR options.
2963 \fB[\fB-e\fR] \fIperm\fR|@\fIsetname\fR[,...]\fR
2967 Specifies that the permissions be delegated to "everyone." Multiple permissions may be specified as a comma-separated list. Permission names are the same as \fBZFS\fR subcommand and property names. See the property list below. Property set names, which begin with an at sign (\fB@\fR) , may be specified. See the \fB-s\fR form below for details.
2973 \fB[\fB-ld\fR] \fIfilesystem\fR|\fIvolume\fR\fR
2977 Specifies where the permissions are delegated. If neither of the \fB-ld\fR options are specified, or both are, then the permissions are allowed for the file system or volume, and all of its descendents. If only the \fB-l\fR option is used, then is allowed "locally" only for the specified file system. If only the \fB-d\fR option is used, then is allowed only for the descendent file systems.
2984 Permissions are generally the ability to use a \fBzfs\fR subcommand or change a property. The following permissions are available:
2989 allow subcommand Must also have the permission that is being
2991 clone subcommand Must also have the 'create' ability and 'mount'
2992 ability in the origin file system
2993 create subcommand Must also have the 'mount' ability
2994 destroy subcommand Must also have the 'mount' ability
2995 diff subcommand Allows lookup of paths within a dataset
2996 given an object number, and the ability to
2997 create snapshots necessary to 'zfs diff'.
2998 mount subcommand Allows mount/umount of ZFS datasets
2999 promote subcommand Must also have the 'mount'
3000 and 'promote' ability in the origin file system
3001 receive subcommand Must also have the 'mount' and 'create' ability
3002 rename subcommand Must also have the 'mount' and 'create'
3003 ability in the new parent
3004 rollback subcommand Must also have the 'mount' ability
3006 share subcommand Allows sharing file systems over NFS or SMB
3008 snapshot subcommand Must also have the 'mount' ability
3009 groupquota other Allows accessing any groupquota@... property
3010 groupused other Allows reading any groupused@... property
3011 userprop other Allows changing any user property
3012 userquota other Allows accessing any userquota@... property
3013 userused other Allows reading any userused@... property
3019 casesensitivity property
3021 compression property
3026 filesystem_limit property
3031 normalization property
3032 primarycache property
3037 refreservation property
3038 reservation property
3039 secondarycache property
3044 snapshot_limit property
3047 volblocksize property
3059 \fB\fBzfs allow\fR \fB-c\fR \fIperm\fR|@\fIsetname\fR[,...] \fIfilesystem\fR|\fIvolume\fR\fR
3063 Sets "create time" permissions. These permissions are granted (locally) to the creator of any newly-created descendent file system.
3069 \fB\fBzfs allow\fR \fB-s\fR @\fIsetname\fR \fIperm\fR|@\fIsetname\fR[,...] \fIfilesystem\fR|\fIvolume\fR\fR
3073 Defines or adds permissions to a permission set. The set can be used by other \fBzfs allow\fR commands for the specified file system and its descendents. Sets are evaluated dynamically, so changes to a set are immediately reflected. Permission sets follow the same naming restrictions as ZFS file systems, but the name must begin with an "at sign" (\fB@\fR), and can be no more than 64 characters long.
3079 \fB\fBzfs unallow\fR [\fB-rldug\fR] "\fIeveryone\fR"|\fIuser\fR|\fIgroup\fR[,...] [\fIperm\fR|@\fIsetname\fR[, ...]] \fIfilesystem\fR|\fIvolume\fR\fR
3083 \fB\fBzfs unallow\fR [\fB-rld\fR] \fB-e\fR [\fIperm\fR|@\fIsetname\fR [,...]] \fIfilesystem\fR|\fIvolume\fR\fR
3087 \fB\fBzfs unallow\fR [\fB-r\fR] \fB-c\fR [\fIperm\fR|@\fIsetname\fR[,...]]\fR \fB\fIfilesystem\fR|\fIvolume\fR\fR
3091 Removes permissions that were granted with the \fBzfs allow\fR command. No permissions are explicitly denied, so other permissions granted are still in effect. For example, if the permission is granted by an ancestor. If no permissions are specified, then all permissions for the specified \fIuser\fR, \fIgroup\fR, or \fIeveryone\fR are removed. Specifying "everyone" (or using the \fB-e\fR option) only removes the permissions that were granted to "everyone", not all permissions for every user and group. See the \fBzfs allow\fR command for a description of the \fB-ldugec\fR options.
3099 Recursively remove the permissions from this file system and all descendents.
3107 \fB\fBzfs unallow\fR [\fB-r\fR] \fB-s\fR @\fIsetname\fR [\fIperm\fR|@\fIsetname\fR[,...]]\fR \fB\fIfilesystem\fR|\fIvolume\fR\fR
3111 Removes permissions from a permission set. If no permissions are specified, then all permissions are removed, thus removing the set entirely.
3117 \fB\fBzfs hold\fR [\fB-r\fR] \fItag\fR \fIsnapshot\fR...\fR
3121 Adds a single reference, named with the \fItag\fR argument, to the specified snapshot or snapshots. Each snapshot has its own tag namespace, and tags must be unique within that space.
3123 If a hold exists on a snapshot, attempts to destroy that snapshot by using the \fBzfs destroy\fR command return \fBEBUSY\fR.
3131 Specifies that a hold with the given tag is applied recursively to the snapshots of all descendent file systems.
3139 \fB\fBzfs holds\fR [\fB-r\fR] \fIsnapshot\fR...\fR
3143 Lists all existing user references for the given snapshot or snapshots.
3151 Lists the holds that are set on the named descendent snapshots, in addition to listing the holds on the named snapshot.
3159 \fB\fBzfs release\fR [\fB-r\fR] \fItag\fR \fIsnapshot\fR...\fR
3163 Removes a single reference, named with the \fItag\fR argument, from the specified snapshot or snapshots. The tag must already exist for each snapshot.
3171 Recursively releases a hold with the given tag on the snapshots of all descendent file systems.
3179 \fB\fBzfs diff\fR [\fB-FHt\fR] \fIsnapshot\fR \fIsnapshot|filesystem\fR
3183 Display the difference between a snapshot of a given filesystem and another
3184 snapshot of that filesystem from a later time or the current contents of the
3185 filesystem. The first column is a character indicating the type of change,
3186 the other columns indicate pathname, new pathname (in case of rename), change
3187 in link count, and optionally file type and/or change time.
3189 The types of change are:
3192 - The path has been removed
3193 + The path has been created
3194 M The path has been modified
3195 R The path has been renamed
3205 Display an indication of the type of file, in a manner similar to the \fB-F\fR
3206 option of \fBls\fR(1).
3228 Give more parsable tab-separated output, without header lines and without arrows.
3237 Display the path's inode change time as the first column of output.
3242 \fBExample 1 \fRCreating a ZFS File System Hierarchy
3245 The following commands create a file system named \fBpool/home\fR and a file system named \fBpool/home/bob\fR. The mount point \fB/export/home\fR is set for the parent file system, and is automatically inherited by the child file system.
3250 # \fBzfs create pool/home\fR
3251 # \fBzfs set mountpoint=/export/home pool/home\fR
3252 # \fBzfs create pool/home/bob\fR
3258 \fBExample 2 \fRCreating a ZFS Snapshot
3261 The following command creates a snapshot named \fBbackup\fR. This snapshot is mounted on demand in the \fB\&.zfs/snapshot\fR directory at the root of the \fBpool/home/bob\fR file system.
3266 # \fBzfs snapshot pool/home/bob@backup\fR
3272 \fBExample 3 \fRCreating and Destroying Multiple Snapshots
3275 The following command creates snapshots named \fBbackup\fR of \fBpool/home\fR and all of its descendent file systems. Each snapshot is mounted on demand in the \fB\&.zfs/snapshot\fR directory at the root of its file system. The second command destroys the newly created snapshots.
3280 # \fBzfs snapshot -r pool/home@backup\fR
3281 # \fBzfs destroy -r pool/home@backup\fR
3287 \fBExample 4 \fRDisabling and Enabling File System Compression
3290 The following command disables the \fBcompression\fR property for all file systems under \fBpool/home\fR. The next command explicitly enables \fBcompression\fR for \fBpool/home/anne\fR.
3295 # \fBzfs set compression=off pool/home\fR
3296 # \fBzfs set compression=on pool/home/anne\fR
3302 \fBExample 5 \fRListing ZFS Datasets
3305 The following command lists all active file systems and volumes in the system. Snapshots are displayed if the pool's \fBlistsnapshots\fR property is \fBon\fR (the default is \fBoff\fR). See \fBzpool\fR(8) for more information on pool properties.
3311 NAME USED AVAIL REFER MOUNTPOINT
3312 pool 450K 457G 18K /pool
3313 pool/home 315K 457G 21K /export/home
3314 pool/home/anne 18K 457G 18K /export/home/anne
3315 pool/home/bob 276K 457G 276K /export/home/bob
3321 \fBExample 6 \fRSetting a Quota on a ZFS File System
3324 The following command sets a quota of 50 GiB for \fBpool/home/bob\fR.
3329 # \fBzfs set quota=50G pool/home/bob\fR
3335 \fBExample 7 \fRListing ZFS Properties
3338 The following command lists all properties for \fBpool/home/bob\fR.
3343 # \fBzfs get all pool/home/bob\fR
3344 NAME PROPERTY VALUE SOURCE
3345 pool/home/bob type filesystem -
3346 pool/home/bob creation Tue Jul 21 15:53 2009 -
3347 pool/home/bob used 21K -
3348 pool/home/bob available 20.0G -
3349 pool/home/bob referenced 21K -
3350 pool/home/bob compressratio 1.00x -
3351 pool/home/bob mounted yes -
3352 pool/home/bob quota 20G local
3353 pool/home/bob reservation none default
3354 pool/home/bob recordsize 128K default
3355 pool/home/bob mountpoint /pool/home/bob default
3356 pool/home/bob sharenfs off default
3357 pool/home/bob checksum on default
3358 pool/home/bob compression on local
3359 pool/home/bob atime on default
3360 pool/home/bob devices on default
3361 pool/home/bob exec on default
3362 pool/home/bob setuid on default
3363 pool/home/bob readonly off default
3364 pool/home/bob zoned off default
3365 pool/home/bob snapdir hidden default
3366 pool/home/bob acltype off default
3367 pool/home/bob aclinherit restricted default
3368 pool/home/bob canmount on default
3369 pool/home/bob xattr on default
3370 pool/home/bob copies 1 default
3371 pool/home/bob version 4 -
3372 pool/home/bob utf8only off -
3373 pool/home/bob normalization none -
3374 pool/home/bob casesensitivity sensitive -
3375 pool/home/bob vscan off default
3376 pool/home/bob nbmand off default
3377 pool/home/bob sharesmb off default
3378 pool/home/bob refquota none default
3379 pool/home/bob refreservation none default
3380 pool/home/bob primarycache all default
3381 pool/home/bob secondarycache all default
3382 pool/home/bob usedbysnapshots 0 -
3383 pool/home/bob usedbydataset 21K -
3384 pool/home/bob usedbychildren 0 -
3385 pool/home/bob usedbyrefreservation 0 -
3386 pool/home/bob logbias latency default
3387 pool/home/bob dedup off default
3388 pool/home/bob mlslabel none default
3389 pool/home/bob relatime off default
3396 The following command gets a single property value.
3401 # \fBzfs get -H -o value compression pool/home/bob\fR
3409 The following command lists all properties with local settings for \fBpool/home/bob\fR.
3414 # \fBzfs get -r -s local -o name,property,value all pool/home/bob\fR
3416 pool/home/bob quota 20G
3417 pool/home/bob compression on
3423 \fBExample 8 \fRRolling Back a ZFS File System
3426 The following command reverts the contents of \fBpool/home/anne\fR to the snapshot named \fByesterday\fR, deleting all intermediate snapshots.
3431 # \fBzfs rollback -r pool/home/anne@yesterday\fR
3437 \fBExample 9 \fRCreating a ZFS Clone
3440 The following command creates a writable file system whose initial contents are the same as \fBpool/home/bob@yesterday\fR.
3445 # \fBzfs clone pool/home/bob@yesterday pool/clone\fR
3451 \fBExample 10 \fRPromoting a ZFS Clone
3454 The following commands illustrate how to test out changes to a file system, and then replace the original file system with the changed one, using clones, clone promotion, and renaming:
3459 # \fBzfs create pool/project/production\fR
3460 populate /pool/project/production with data
3461 # \fBzfs snapshot pool/project/production@today\fR
3462 # \fBzfs clone pool/project/production@today pool/project/beta\fR
3463 make changes to /pool/project/beta and test them
3464 # \fBzfs promote pool/project/beta\fR
3465 # \fBzfs rename pool/project/production pool/project/legacy\fR
3466 # \fBzfs rename pool/project/beta pool/project/production\fR
3467 once the legacy version is no longer needed, it can be destroyed
3468 # \fBzfs destroy pool/project/legacy\fR
3474 \fBExample 11 \fRInheriting ZFS Properties
3477 The following command causes \fBpool/home/bob\fR and \fBpool/home/anne\fR to inherit the \fBchecksum\fR property from their parent.
3482 # \fBzfs inherit checksum pool/home/bob pool/home/anne\fR
3487 The following command causes \fBpool/home/bob\fR to revert to the received
3488 value for the \fBquota\fR property if it exists.
3493 # \fBzfs inherit -S quota pool/home/bob
3499 \fBExample 12 \fRRemotely Replicating ZFS Data
3502 The following commands send a full stream and then an incremental stream to a remote machine, restoring them into \fBpoolB/received/fs@a\fRand \fBpoolB/received/fs@b\fR, respectively. \fBpoolB\fR must contain the file system \fBpoolB/received\fR, and must not initially contain \fBpoolB/received/fs\fR.
3507 # \fBzfs send pool/fs@a | \e\fR
3508 \fBssh host zfs receive poolB/received/fs@a\fR
3509 # \fBzfs send -i a pool/fs@b | ssh host \e\fR
3510 \fBzfs receive poolB/received/fs\fR
3516 \fBExample 13 \fRUsing the \fBzfs receive\fR \fB-d\fR Option
3519 The following command sends a full stream of \fBpoolA/fsA/fsB@snap\fR to a remote machine, receiving it into \fBpoolB/received/fsA/fsB@snap\fR. The \fBfsA/fsB@snap\fR portion of the received snapshot's name is determined from the name of the sent snapshot. \fBpoolB\fR must contain the file system \fBpoolB/received\fR. If \fBpoolB/received/fsA\fR does not exist, it is created as an empty file system.
3524 # \fBzfs send poolA/fsA/fsB@snap | \e
3525 ssh host zfs receive -d poolB/received\fR
3531 \fBExample 14 \fRSetting User Properties
3534 The following example sets the user-defined \fBcom.example:department\fR property for a dataset.
3539 # \fBzfs set com.example:department=12345 tank/accounting\fR
3545 \fBExample 15 \fRPerforming a Rolling Snapshot
3548 The following example shows how to maintain a history of snapshots with a consistent naming scheme. To keep a week's worth of snapshots, the user destroys the oldest snapshot, renames the remaining snapshots, and then creates a new snapshot, as follows:
3553 # \fBzfs destroy -r pool/users@7daysago\fR
3554 # \fBzfs rename -r pool/users@6daysago @7daysago\fR
3555 # \fBzfs rename -r pool/users@5daysago @6daysago\fR
3556 # \fBzfs rename -r pool/users@4daysago @5daysago\fR
3557 # \fBzfs rename -r pool/users@3daysago @4daysago\fR
3558 # \fBzfs rename -r pool/users@2daysago @3daysago\fR
3559 # \fBzfs rename -r pool/users@yesterday @2daysago\fR
3560 # \fBzfs rename -r pool/users@today @yesterday\fR
3561 # \fBzfs snapshot -r pool/users@today\fR
3567 \fBExample 16 \fRSetting \fBsharenfs\fR Property Options on a ZFS File System
3570 The following commands show how to set \fBsharenfs\fR property options to enable \fBrw\fR access for a set of \fBIP\fR addresses and to enable root access for system \fBneo\fR on the \fBtank/home\fR file system.
3575 # \fBzfs set sharenfs='rw=@123.123.0.0/16,root=neo' tank/home\fR
3582 If you are using \fBDNS\fR for host name resolution, specify the fully qualified hostname.
3585 \fBExample 17 \fRDelegating ZFS Administration Permissions on a ZFS Dataset
3588 This is not currently supported on Linux.
3590 The following example shows how to set permissions so that user \fBcindys\fR can create, destroy, mount, and take snapshots on \fBtank/cindys\fR. The permissions on \fBtank/cindys\fR are also displayed.
3595 # \fBzfs allow cindys create,destroy,mount,snapshot tank/cindys\fR
3596 # \fBzfs allow tank/cindys\fR
3597 -------------------------------------------------------------
3598 Local+Descendent permissions on (tank/cindys)
3599 user cindys create,destroy,mount,snapshot
3600 -------------------------------------------------------------
3607 Because the \fBtank/cindys\fR mount point permission is set to 755 by default, user \fBcindys\fR will be unable to mount file systems under \fBtank/cindys\fR. Set an \fBACL\fR similar to the following syntax to provide mount point access:
3611 # \fBchmod A+user:cindys:add_subdirectory:allow /tank/cindys\fR
3617 \fBExample 18 \fRDelegating Create Time Permissions on a ZFS Dataset
3620 The following example shows how to grant anyone in the group \fBstaff\fR to create file systems in \fBtank/users\fR. This syntax also allows staff members to destroy their own file systems, but not destroy anyone else's file system. The permissions on \fBtank/users\fR are also displayed.
3625 # \fBzfs allow staff create,mount tank/users\fR
3626 # \fBzfs allow -c destroy tank/users\fR
3627 # \fBzfs allow tank/users\fR
3628 -------------------------------------------------------------
3629 Create time permissions on (tank/users)
3631 Local+Descendent permissions on (tank/users)
3632 group staff create,mount
3633 -------------------------------------------------------------
3639 \fBExample 19 \fRDefining and Granting a Permission Set on a ZFS Dataset
3642 The following example shows how to define and grant a permission set on the \fBtank/users\fR file system. The permissions on \fBtank/users\fR are also displayed.
3647 # \fBzfs allow -s @pset create,destroy,snapshot,mount tank/users\fR
3648 # \fBzfs allow staff @pset tank/users\fR
3649 # \fBzfs allow tank/users\fR
3650 -------------------------------------------------------------
3651 Permission sets on (tank/users)
3652 @pset create,destroy,mount,snapshot
3653 Create time permissions on (tank/users)
3655 Local+Descendent permissions on (tank/users)
3656 group staff @pset,create,mount
3657 -------------------------------------------------------------
3663 \fBExample 20 \fRDelegating Property Permissions on a ZFS Dataset
3666 The following example shows to grant the ability to set quotas and reservations on the \fBusers/home\fR file system. The permissions on \fBusers/home\fR are also displayed.
3671 # \fBzfs allow cindys quota,reservation users/home\fR
3672 # \fBzfs allow users/home\fR
3673 -------------------------------------------------------------
3674 Local+Descendent permissions on (users/home)
3675 user cindys quota,reservation
3676 -------------------------------------------------------------
3677 cindys% \fBzfs set quota=10G users/home/marks\fR
3678 cindys% \fBzfs get quota users/home/marks\fR
3679 NAME PROPERTY VALUE SOURCE
3680 users/home/marks quota 10G local
3686 \fBExample 21 \fRRemoving ZFS Delegated Permissions on a ZFS Dataset
3689 The following example shows how to remove the snapshot permission from the \fBstaff\fR group on the \fBtank/users\fR file system. The permissions on \fBtank/users\fR are also displayed.
3694 # \fBzfs unallow staff snapshot tank/users\fR
3695 # \fBzfs allow tank/users\fR
3696 -------------------------------------------------------------
3697 Permission sets on (tank/users)
3698 @pset create,destroy,mount,snapshot
3699 Create time permissions on (tank/users)
3701 Local+Descendent permissions on (tank/users)
3702 group staff @pset,create,mount
3703 -------------------------------------------------------------
3709 \fBExample 22\fR Showing the differences between a snapshot and a ZFS Dataset
3712 The following example shows how to see what has changed between a prior
3713 snapshot of a ZFS Dataset and its current state. The \fB-F\fR option is used
3714 to indicate type information for the files affected.
3719 # zfs diff -F tank/test@before tank/test
3721 M F /tank/test/linked (+1)
3722 R F /tank/test/oldname -> /tank/test/newname
3723 - F /tank/test/deleted
3724 + F /tank/test/created
3725 M F /tank/test/modified
3731 \fBExample 23\fR Creating a bookmark
3734 The following example create a bookmark to a snapshot. This bookmark can then
3735 be used instead of snapshot in send streams.
3740 # zfs bookmark rpool@snapshot rpool#bookmark
3745 .SH "ENVIRONMENT VARIABLES"
3748 Cause \fBzfs\fR to dump core on exit for the purposes of running \fB::findleaks\fR.
3752 The following exit values are returned:
3760 Successful completion.
3780 Invalid command line options were specified.
3785 \fBchmod\fR(2), \fBfsync\fR(2), \fBgzip\fR(1), \fBls\fR(1), \fBmount\fR(8), \fBopen\fR(2), \fBreaddir\fR(3), \fBssh\fR(1), \fBstat\fR(2), \fBwrite\fR(2), \fBzpool\fR(8), \fBzfs-module-parameters\fR(5)
3787 On Solaris: \fBdfstab(4)\fR, \fBiscsitadm(1M)\fR, \fBmount(1M)\fR, \fBshare(1M)\fR, \fBsharemgr(1M)\fR, \fBunshare(1M)\fR
projects / mirror_zfs.git / blob