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 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 full 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="<d,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 |GlusterFS      |glusterfs   |file  |yes   |no^1^    |yes
  76 |CephFS         |cephfs      |file  |yes   |yes      |yes
  77 |LVM            |lvm         |block |no^2^ |no       |yes
  78 |LVM-thin       |lvmthin     |block |no    |yes      |yes
  79 |iSCSI/kernel   |iscsi       |block |yes   |no       |yes
  80 |iSCSI/libiscsi |iscsidirect |block |yes   |no       |yes
  81 |Ceph/RBD       |rbd         |block |yes   |yes      |yes
  82 |ZFS over iSCSI |zfs         |block |yes   |yes      |yes
  83 |=========================================================
  84
  85 ^1^: On file based storages, snapshots are possible with the 'qcow2' format.
  86
  87 ^2^: It is possible to use LVM on top of an iSCSI storage. That way
  88 you get a `shared` LVM storage.
  89
  90
  91 Thin Provisioning
  92 ~~~~~~~~~~~~~~~~~
  93
  94 A number of storages, and the Qemu image format `qcow2`, support 'thin
  95 provisioning'.  With thin provisioning activated, only the blocks that
  96 the guest system actually use will be written to the storage.
  97
  98 Say for instance you create a VM with a 32GB hard disk, and after
  99 installing the guest system OS, the root file system of the VM contains
 100 3 GB of data.  In that case only 3GB are written to the storage, even
 101 if the guest VM sees a 32GB hard drive. In this way thin provisioning
 102 allows you to create disk images which are larger than the currently
 103 available storage blocks. You can create large disk images for your
 104 VMs, and when the need arises, add more disks to your storage without
 105 resizing the VMs' file systems.
 106
 107 All storage types which have the ``Snapshots'' feature also support thin
 108 provisioning.
 109
 110 CAUTION: If a storage runs full, all guests using volumes on that
 111 storage receive IO errors. This can cause file system inconsistencies
 112 and may corrupt your data. So it is advisable to avoid
 113 over-provisioning of your storage resources, or carefully observe
 114 free space to avoid such conditions.
 115
 116
 117 Storage Configuration
 118 ---------------------
 119
 120 All {pve} related storage configuration is stored within a single text
 121 file at `/etc/pve/storage.cfg`. As this file is within `/etc/pve/`, it
 122 gets automatically distributed to all cluster nodes. So all nodes
 123 share the same storage configuration.
 124
 125 Sharing storage configuration make perfect sense for shared storage,
 126 because the same ``shared'' storage is accessible from all nodes. But is
 127 also useful for local storage types. In this case such local storage
 128 is available on all nodes, but it is physically different and can have
 129 totally different content.
 130
 131
 132 Storage Pools
 133 ~~~~~~~~~~~~~
 134
 135 Each storage pool has a `<type>`, and is uniquely identified by its
 136 `<STORAGE_ID>`. A pool configuration looks like this:
 137
 138 ----
 139 <type>: <STORAGE_ID>
 140         <property> <value>
 141         <property> <value>
 142         ...
 143 ----
 144
 145 The `<type>: <STORAGE_ID>` line starts the pool definition, which is then
 146 followed by a list of properties. Most properties have values, but some of
 147 them come with reasonable default. In that case you can omit the value.
 148
 149 To be more specific, take a look at the default storage configuration
 150 after installation. It contains one special local storage pool named
 151 `local`, which refers to the directory `/var/lib/vz` and is always
 152 available. The {pve} installer creates additional storage entries
 153 depending on the storage type chosen at installation time.
 154
 155 .Default storage configuration (`/etc/pve/storage.cfg`)
 156 ----
 157 dir: local
 158         path /var/lib/vz
 159         content iso,vztmpl,backup
 160
 161 # default image store on LVM based installation
 162 lvmthin: local-lvm
 163         thinpool data
 164         vgname pve
 165         content rootdir,images
 166
 167 # default image store on ZFS based installation
 168 zfspool: local-zfs
 169         pool rpool/data
 170         sparse
 171         content images,rootdir
 172 ----
 173
 174
 175 Common Storage Properties
 176 ~~~~~~~~~~~~~~~~~~~~~~~~~
 177
 178 A few storage properties are common among different storage types.
 179
 180 nodes::
 181
 182 List of cluster node names where this storage is
 183 usable/accessible. One can use this property to restrict storage
 184 access to a limited set of nodes.
 185
 186 content::
 187
 188 A storage can support several content types, for example virtual disk
 189 images, cdrom iso images, container templates or container root
 190 directories. Not all storage types support all content types. One can set
 191 this property to select for what this storage is used for.
 192
 193 images:::
 194
 195 KVM-Qemu VM images.
 196
 197 rootdir:::
 198
 199 Allow to store container data.
 200
 201 vztmpl:::
 202
 203 Container templates.
 204
 205 backup:::
 206
 207 Backup files (`vzdump`).
 208
 209 iso:::
 210
 211 ISO images
 212
 213 snippets:::
 214
 215 Snippet files, for example guest hook scripts
 216
 217 shared::
 218
 219 Mark storage as shared.
 220
 221 disable::
 222
 223 You can use this flag to disable the storage completely.
 224
 225 maxfiles::
 226
 227 Maximum number of backup files per VM. Use `0` for unlimited.
 228
 229 format::
 230
 231 Default image format (`raw|qcow2|vmdk`)
 232
 233
 234 WARNING: It is not advisable to use the same storage pool on different
 235 {pve} clusters. Some storage operation need exclusive access to the
 236 storage, so proper locking is required. While this is implemented
 237 within a cluster, it does not work between different clusters.
 238
 239
 240 Volumes
 241 -------
 242
 243 We use a special notation to address storage data. When you allocate
 244 data from a storage pool, it returns such a volume identifier. A volume
 245 is identified by the `<STORAGE_ID>`, followed by a storage type
 246 dependent volume name, separated by colon. A valid `<VOLUME_ID>` looks
 247 like:
 248
 249  local:230/example-image.raw
 250
 251  local:iso/debian-501-amd64-netinst.iso
 252
 253  local:vztmpl/debian-5.0-joomla_1.5.9-1_i386.tar.gz
 254
 255  iscsi-storage:0.0.2.scsi-14f504e46494c4500494b5042546d2d646744372d31616d61
 256
 257 To get the file system path for a `<VOLUME_ID>` use:
 258
 259  pvesm path <VOLUME_ID>
 260
 261
 262 Volume Ownership
 263 ~~~~~~~~~~~~~~~~
 264
 265 There exists an ownership relation for `image` type volumes. Each such
 266 volume is owned by a VM or Container. For example volume
 267 `local:230/example-image.raw` is owned by VM 230. Most storage
 268 backends encodes this ownership information into the volume name.
 269
 270 When you remove a VM or Container, the system also removes all
 271 associated volumes which are owned by that VM or Container.
 272
 273
 274 Using the Command Line Interface
 275 --------------------------------
 276
 277 It is recommended to familiarize yourself with the concept behind storage
 278 pools and volume identifiers, but in real life, you are not forced to do any
 279 of those low level operations on the command line. Normally,
 280 allocation and removal of volumes is done by the VM and Container
 281 management tools.
 282
 283 Nevertheless, there is a command line tool called `pvesm` (``{pve}
 284 Storage Manager''), which is able to perform common storage management
 285 tasks.
 286
 287
 288 Examples
 289 ~~~~~~~~
 290
 291 Add storage pools
 292
 293  pvesm add <TYPE> <STORAGE_ID> <OPTIONS>
 294  pvesm add dir <STORAGE_ID> --path <PATH>
 295  pvesm add nfs <STORAGE_ID> --path <PATH> --server <SERVER> --export <EXPORT>
 296  pvesm add lvm <STORAGE_ID> --vgname <VGNAME>
 297  pvesm add iscsi <STORAGE_ID> --portal <HOST[:PORT]> --target <TARGET>
 298
 299 Disable storage pools
 300
 301  pvesm set <STORAGE_ID> --disable 1
 302
 303 Enable storage pools
 304
 305  pvesm set <STORAGE_ID> --disable 0
 306
 307 Change/set storage options
 308
 309  pvesm set <STORAGE_ID> <OPTIONS>
 310  pvesm set <STORAGE_ID> --shared 1
 311  pvesm set local --format qcow2
 312  pvesm set <STORAGE_ID> --content iso
 313
 314 Remove storage pools. This does not delete any data, and does not
 315 disconnect or unmount anything. It just removes the storage
 316 configuration.
 317
 318  pvesm remove <STORAGE_ID>
 319
 320 Allocate volumes
 321
 322  pvesm alloc <STORAGE_ID> <VMID> <name> <size> [--format <raw|qcow2>]
 323
 324 Allocate a 4G volume in local storage. The name is auto-generated if
 325 you pass an empty string as `<name>`
 326
 327  pvesm alloc local <VMID> '' 4G
 328
 329 Free volumes
 330
 331  pvesm free <VOLUME_ID>
 332
 333 WARNING: This really destroys all volume data.
 334
 335 List storage status
 336
 337  pvesm status
 338
 339 List storage contents
 340
 341  pvesm list <STORAGE_ID> [--vmid <VMID>]
 342
 343 List volumes allocated by VMID
 344
 345  pvesm list <STORAGE_ID> --vmid <VMID>
 346
 347 List iso images
 348
 349  pvesm list <STORAGE_ID> --iso
 350
 351 List container templates
 352
 353  pvesm list <STORAGE_ID> --vztmpl
 354
 355 Show file system path for a volume
 356
 357  pvesm path <VOLUME_ID>
 358
 359 ifdef::wiki[]
 360
 361 See Also
 362 --------
 363
 364 * link:/wiki/Storage:_Directory[Storage: Directory]
 365
 366 * link:/wiki/Storage:_GlusterFS[Storage: GlusterFS]
 367
 368 * link:/wiki/Storage:_User_Mode_iSCSI[Storage: User Mode iSCSI]
 369
 370 * link:/wiki/Storage:_iSCSI[Storage: iSCSI]
 371
 372 * link:/wiki/Storage:_LVM[Storage: LVM]
 373
 374 * link:/wiki/Storage:_LVM_Thin[Storage: LVM Thin]
 375
 376 * link:/wiki/Storage:_NFS[Storage: NFS]
 377
 378 * link:/wiki/Storage:_CIFS[Storage: CIFS]
 379
 380 * link:/wiki/Storage:_RBD[Storage: RBD]
 381
 382 * link:/wiki/Storage:_CephFS[Storage: CephFS]
 383
 384 * link:/wiki/Storage:_ZFS[Storage: ZFS]
 385
 386 * link:/wiki/Storage:_ZFS_over_iSCSI[Storage: ZFS over iSCSI]
 387
 388 endif::wiki[]
 389
 390 ifndef::wiki[]
 391
 392 // backend documentation
 393
 394 include::pve-storage-dir.adoc[]
 395
 396 include::pve-storage-nfs.adoc[]
 397
 398 include::pve-storage-cifs.adoc[]
 399
 400 include::pve-storage-glusterfs.adoc[]
 401
 402 include::pve-storage-zfspool.adoc[]
 403
 404 include::pve-storage-lvm.adoc[]
 405
 406 include::pve-storage-lvmthin.adoc[]
 407
 408 include::pve-storage-iscsi.adoc[]
 409
 410 include::pve-storage-iscsidirect.adoc[]
 411
 412 include::pve-storage-rbd.adoc[]
 413
 414 include::pve-storage-cephfs.adoc[]
 415
 416
 417
 418 ifdef::manvolnum[]
 419 include::pve-copyright.adoc[]
 420 endif::manvolnum[]
 421
 422 endif::wiki[]
 423