pvesm.adoc

   1 [[chapter_storage]]
   2 ifdef::manvolnum[]
   3 pvesm(1)
   4 ========
   5 :pve-toplevel:
   6
   7 NAME
   8 ----
   9
  10 pvesm - Proxmox VE Storage Manager
  11
  12
  13 SYNOPSIS
  14 --------
  15
  16 include::pvesm.1-synopsis.adoc[]
  17
  18 DESCRIPTION
  19 -----------
  20 endif::manvolnum[]
  21 ifndef::manvolnum[]
  22 {pve} Storage
  23 =============
  24 :pve-toplevel:
  25 endif::manvolnum[]
  26 ifdef::wiki[]
  27 :title: Storage
  28 endif::wiki[]
  29
  30 The {pve} storage model is very flexible. Virtual machine images
  31 can either be stored on one or several local storages, or on shared
  32 storage like NFS or iSCSI (NAS, SAN). There are no limits, and you may
  33 configure as many storage pools as you like. You can use all
  34 storage technologies available for Debian Linux.
  35
  36 One major benefit of storing VMs on shared storage is the ability to
  37 live-migrate running machines without any downtime, as all nodes in
  38 the cluster have direct access to VM disk images. There is no need to
  39 copy VM image data, so live migration is very fast in that case.
  40
  41 The storage library (package `libpve-storage-perl`) uses a flexible
  42 plugin system to provide a common interface to all storage types. This
  43 can be easily adopted to include further storage types in the future.
  44
  45
  46 Storage Types
  47 -------------
  48
  49 There are basically two different classes of storage types:
  50
  51 File level storage::
  52
  53 File level based storage technologies allow access to a fully featured (POSIX)
  54 file system.  They are in general more flexible than any Block level storage
  55 (see below), and allow you to store content of any type. ZFS is probably the
  56 most advanced system, and it has full support for snapshots and clones.
  57
  58 Block level storage::
  59
  60 Allows to store large 'raw' images. It is usually not possible to store
  61 other files (ISO, backups, ..) on such storage types. Most modern
  62 block level storage implementations support snapshots and clones.
  63 RADOS and GlusterFS are distributed systems, replicating storage
  64 data to different nodes.
  65
  66
  67 .Available storage types
  68 [width="100%",cols="<2d,1*m,4*d",options="header"]
  69 |===========================================================
  70 |Description    |PVE type    |Level |Shared|Snapshots|Stable
  71 |ZFS (local)    |zfspool     |file  |no    |yes      |yes
  72 |Directory      |dir         |file  |no    |no^1^    |yes
  73 |NFS            |nfs         |file  |yes   |no^1^    |yes
  74 |CIFS           |cifs        |file  |yes   |no^1^    |yes
  75 |Proxmox Backup |pbs         |both  |yes   |n/a      |beta
  76 |GlusterFS      |glusterfs   |file  |yes   |no^1^    |yes
  77 |CephFS         |cephfs      |file  |yes   |yes      |yes
  78 |LVM            |lvm         |block |no^2^ |no       |yes
  79 |LVM-thin       |lvmthin     |block |no    |yes      |yes
  80 |iSCSI/kernel   |iscsi       |block |yes   |no       |yes
  81 |iSCSI/libiscsi |iscsidirect |block |yes   |no       |yes
  82 |Ceph/RBD       |rbd         |block |yes   |yes      |yes
  83 |ZFS over iSCSI |zfs         |block |yes   |yes      |yes
  84 |===========================================================
  85
  86 ^1^: On file based storages, snapshots are possible with the 'qcow2' format.
  87
  88 ^2^: It is possible to use LVM on top of an iSCSI or FC-based storage.
  89 That way you get a `shared` LVM storage.
  90
  91
  92 Thin Provisioning
  93 ~~~~~~~~~~~~~~~~~
  94
  95 A number of storages, and the Qemu image format `qcow2`, support 'thin
  96 provisioning'.  With thin provisioning activated, only the blocks that
  97 the guest system actually use will be written to the storage.
  98
  99 Say for instance you create a VM with a 32GB hard disk, and after
 100 installing the guest system OS, the root file system of the VM contains
 101 3 GB of data.  In that case only 3GB are written to the storage, even
 102 if the guest VM sees a 32GB hard drive. In this way thin provisioning
 103 allows you to create disk images which are larger than the currently
 104 available storage blocks. You can create large disk images for your
 105 VMs, and when the need arises, add more disks to your storage without
 106 resizing the VMs' file systems.
 107
 108 All storage types which have the ``Snapshots'' feature also support thin
 109 provisioning.
 110
 111 CAUTION: If a storage runs full, all guests using volumes on that
 112 storage receive IO errors. This can cause file system inconsistencies
 113 and may corrupt your data. So it is advisable to avoid
 114 over-provisioning of your storage resources, or carefully observe
 115 free space to avoid such conditions.
 116
 117
 118 Storage Configuration
 119 ---------------------
 120
 121 All {pve} related storage configuration is stored within a single text
 122 file at `/etc/pve/storage.cfg`. As this file is within `/etc/pve/`, it
 123 gets automatically distributed to all cluster nodes. So all nodes
 124 share the same storage configuration.
 125
 126 Sharing storage configuration makes perfect sense for shared storage,
 127 because the same ``shared'' storage is accessible from all nodes. But it is
 128 also useful for local storage types. In this case such local storage
 129 is available on all nodes, but it is physically different and can have
 130 totally different content.
 131
 132
 133 Storage Pools
 134 ~~~~~~~~~~~~~
 135
 136 Each storage pool has a `<type>`, and is uniquely identified by its
 137 `<STORAGE_ID>`. A pool configuration looks like this:
 138
 139 ----
 140 <type>: <STORAGE_ID>
 141         <property> <value>
 142         <property> <value>
 143         <property>
 144         ...
 145 ----
 146
 147 The `<type>: <STORAGE_ID>` line starts the pool definition, which is then
 148 followed by a list of properties. Most properties require a value. Some have
 149 reasonable defaults, in which case you can omit the value.
 150
 151 To be more specific, take a look at the default storage configuration
 152 after installation. It contains one special local storage pool named
 153 `local`, which refers to the directory `/var/lib/vz` and is always
 154 available. The {pve} installer creates additional storage entries
 155 depending on the storage type chosen at installation time.
 156
 157 .Default storage configuration (`/etc/pve/storage.cfg`)
 158 ----
 159 dir: local
 160         path /var/lib/vz
 161         content iso,vztmpl,backup
 162
 163 # default image store on LVM based installation
 164 lvmthin: local-lvm
 165         thinpool data
 166         vgname pve
 167         content rootdir,images
 168
 169 # default image store on ZFS based installation
 170 zfspool: local-zfs
 171         pool rpool/data
 172         sparse
 173         content images,rootdir
 174 ----
 175
 176
 177 Common Storage Properties
 178 ~~~~~~~~~~~~~~~~~~~~~~~~~
 179
 180 A few storage properties are common among different storage types.
 181
 182 nodes::
 183
 184 List of cluster node names where this storage is
 185 usable/accessible. One can use this property to restrict storage
 186 access to a limited set of nodes.
 187
 188 content::
 189
 190 A storage can support several content types, for example virtual disk
 191 images, cdrom iso images, container templates or container root
 192 directories. Not all storage types support all content types. One can set
 193 this property to select what this storage is used for.
 194
 195 images:::
 196
 197 KVM-Qemu VM images.
 198
 199 rootdir:::
 200
 201 Allow to store container data.
 202
 203 vztmpl:::
 204
 205 Container templates.
 206
 207 backup:::
 208
 209 Backup files (`vzdump`).
 210
 211 iso:::
 212
 213 ISO images
 214
 215 snippets:::
 216
 217 Snippet files, for example guest hook scripts
 218
 219 shared::
 220
 221 Mark storage as shared.
 222
 223 disable::
 224
 225 You can use this flag to disable the storage completely.
 226
 227 maxfiles::
 228
 229 Deprecated, please use `prune-backups` instead. Maximum number of backup files
 230 per VM. Use `0` for unlimited.
 231
 232 prune-backups::
 233
 234 Retention options for backups. For details, see
 235 xref:vzdump_retention[Backup Retention].
 236
 237 format::
 238
 239 Default image format (`raw|qcow2|vmdk`)
 240
 241
 242 WARNING: It is not advisable to use the same storage pool on different
 243 {pve} clusters. Some storage operation need exclusive access to the
 244 storage, so proper locking is required. While this is implemented
 245 within a cluster, it does not work between different clusters.
 246
 247
 248 Volumes
 249 -------
 250
 251 We use a special notation to address storage data. When you allocate
 252 data from a storage pool, it returns such a volume identifier. A volume
 253 is identified by the `<STORAGE_ID>`, followed by a storage type
 254 dependent volume name, separated by colon. A valid `<VOLUME_ID>` looks
 255 like:
 256
 257  local:230/example-image.raw
 258
 259  local:iso/debian-501-amd64-netinst.iso
 260
 261  local:vztmpl/debian-5.0-joomla_1.5.9-1_i386.tar.gz
 262
 263  iscsi-storage:0.0.2.scsi-14f504e46494c4500494b5042546d2d646744372d31616d61
 264
 265 To get the file system path for a `<VOLUME_ID>` use:
 266
 267  pvesm path <VOLUME_ID>
 268
 269
 270 Volume Ownership
 271 ~~~~~~~~~~~~~~~~
 272
 273 There exists an ownership relation for `image` type volumes. Each such
 274 volume is owned by a VM or Container. For example volume
 275 `local:230/example-image.raw` is owned by VM 230. Most storage
 276 backends encodes this ownership information into the volume name.
 277
 278 When you remove a VM or Container, the system also removes all
 279 associated volumes which are owned by that VM or Container.
 280
 281
 282 Using the Command Line Interface
 283 --------------------------------
 284
 285 It is recommended to familiarize yourself with the concept behind storage
 286 pools and volume identifiers, but in real life, you are not forced to do any
 287 of those low level operations on the command line. Normally,
 288 allocation and removal of volumes is done by the VM and Container
 289 management tools.
 290
 291 Nevertheless, there is a command line tool called `pvesm` (``{pve}
 292 Storage Manager''), which is able to perform common storage management
 293 tasks.
 294
 295
 296 Examples
 297 ~~~~~~~~
 298
 299 Add storage pools
 300
 301  pvesm add <TYPE> <STORAGE_ID> <OPTIONS>
 302  pvesm add dir <STORAGE_ID> --path <PATH>
 303  pvesm add nfs <STORAGE_ID> --path <PATH> --server <SERVER> --export <EXPORT>
 304  pvesm add lvm <STORAGE_ID> --vgname <VGNAME>
 305  pvesm add iscsi <STORAGE_ID> --portal <HOST[:PORT]> --target <TARGET>
 306
 307 Disable storage pools
 308
 309  pvesm set <STORAGE_ID> --disable 1
 310
 311 Enable storage pools
 312
 313  pvesm set <STORAGE_ID> --disable 0
 314
 315 Change/set storage options
 316
 317  pvesm set <STORAGE_ID> <OPTIONS>
 318  pvesm set <STORAGE_ID> --shared 1
 319  pvesm set local --format qcow2
 320  pvesm set <STORAGE_ID> --content iso
 321
 322 Remove storage pools. This does not delete any data, and does not
 323 disconnect or unmount anything. It just removes the storage
 324 configuration.
 325
 326  pvesm remove <STORAGE_ID>
 327
 328 Allocate volumes
 329
 330  pvesm alloc <STORAGE_ID> <VMID> <name> <size> [--format <raw|qcow2>]
 331
 332 Allocate a 4G volume in local storage. The name is auto-generated if
 333 you pass an empty string as `<name>`
 334
 335  pvesm alloc local <VMID> '' 4G
 336
 337 Free volumes
 338
 339  pvesm free <VOLUME_ID>
 340
 341 WARNING: This really destroys all volume data.
 342
 343 List storage status
 344
 345  pvesm status
 346
 347 List storage contents
 348
 349  pvesm list <STORAGE_ID> [--vmid <VMID>]
 350
 351 List volumes allocated by VMID
 352
 353  pvesm list <STORAGE_ID> --vmid <VMID>
 354
 355 List iso images
 356
 357  pvesm list <STORAGE_ID> --iso
 358
 359 List container templates
 360
 361  pvesm list <STORAGE_ID> --vztmpl
 362
 363 Show file system path for a volume
 364
 365  pvesm path <VOLUME_ID>
 366
 367 Exporting the volume `local:103/vm-103-disk-0.qcow2` to the file `target`.
 368 This is mostly used internally with `pvesm import`.
 369 The stream format qcow2+size is different to the qcow2 format.
 370 Consequently, the exported file cannot simply be attached to a VM.
 371 This also holds for the other formats.
 372
 373  pvesm export local:103/vm-103-disk-0.qcow2 qcow2+size target --with-snapshots 1
 374
 375 ifdef::wiki[]
 376
 377 See Also
 378 --------
 379
 380 * link:/wiki/Storage:_Directory[Storage: Directory]
 381
 382 * link:/wiki/Storage:_GlusterFS[Storage: GlusterFS]
 383
 384 * link:/wiki/Storage:_User_Mode_iSCSI[Storage: User Mode iSCSI]
 385
 386 * link:/wiki/Storage:_iSCSI[Storage: iSCSI]
 387
 388 * link:/wiki/Storage:_LVM[Storage: LVM]
 389
 390 * link:/wiki/Storage:_LVM_Thin[Storage: LVM Thin]
 391
 392 * link:/wiki/Storage:_NFS[Storage: NFS]
 393
 394 * link:/wiki/Storage:_CIFS[Storage: CIFS]
 395
 396 * link:/wiki/Storage:_Proxmox_Backup_Server[Storage: Proxmox Backup Server]
 397
 398 * link:/wiki/Storage:_RBD[Storage: RBD]
 399
 400 * link:/wiki/Storage:_CephFS[Storage: CephFS]
 401
 402 * link:/wiki/Storage:_ZFS[Storage: ZFS]
 403
 404 * link:/wiki/Storage:_ZFS_over_iSCSI[Storage: ZFS over iSCSI]
 405
 406 endif::wiki[]
 407
 408 ifndef::wiki[]
 409
 410 // backend documentation
 411
 412 include::pve-storage-dir.adoc[]
 413
 414 include::pve-storage-nfs.adoc[]
 415
 416 include::pve-storage-cifs.adoc[]
 417
 418 include::pve-storage-pbs.adoc[]
 419
 420 include::pve-storage-glusterfs.adoc[]
 421
 422 include::pve-storage-zfspool.adoc[]
 423
 424 include::pve-storage-lvm.adoc[]
 425
 426 include::pve-storage-lvmthin.adoc[]
 427
 428 include::pve-storage-iscsi.adoc[]
 429
 430 include::pve-storage-iscsidirect.adoc[]
 431
 432 include::pve-storage-rbd.adoc[]
 433
 434 include::pve-storage-cephfs.adoc[]
 435
 436
 437
 438 ifdef::manvolnum[]
 439 include::pve-copyright.adoc[]
 440 endif::manvolnum[]
 441
 442 endif::wiki[]
 443