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 Block level storage::
  52
  53 Allows to store large 'raw' images. It is usually not possible to store
  54 other files (ISO, backups, ..) on such storage types. Most modern
  55 block level storage implementations support snapshots and clones.
  56 RADOS, Sheepdog and GlusterFS are distributed systems, replicating storage
  57 data to different nodes.
  58
  59 File level storage::
  60
  61 They allow access to a full featured (POSIX) file system. They are
  62 more flexible, and allows you to store any content type. ZFS is
  63 probably the most advanced system, and it has full support for
  64 snapshots and clones.
  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 |LVM            |lvm         |block |no^2^ |no       |yes
  77 |LVM-thin       |lvmthin     |block |no    |yes      |yes
  78 |iSCSI/kernel   |iscsi       |block |yes   |no       |yes
  79 |iSCSI/libiscsi |iscsidirect |block |yes   |no       |yes
  80 |Ceph/RBD       |rbd         |block |yes   |yes      |yes
  81 |Ceph/CephFS    |cephfs      |file  |yes   |yes      |yes
  82 |Sheepdog       |sheepdog    |block |yes   |yes      |beta
  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 storage. That way
  89 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 make perfect sense for shared storage,
 127 because the same ``shared'' storage is accessible from all nodes. But 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         ...
 144 ----
 145
 146 The `<type>: <STORAGE_ID>` line starts the pool definition, which is then
 147 followed by a list of properties. Most properties have values, but some of
 148 them come with reasonable default. In that case you can omit the value.
 149
 150 To be more specific, take a look at the default storage configuration
 151 after installation. It contains one special local storage pool named
 152 `local`, which refers to the directory `/var/lib/vz` and is always
 153 available. The {pve} installer creates additional storage entries
 154 depending on the storage type chosen at installation time.
 155
 156 .Default storage configuration (`/etc/pve/storage.cfg`)
 157 ----
 158 dir: local
 159         path /var/lib/vz
 160         content iso,vztmpl,backup
 161
 162 # default image store on LVM based installation
 163 lvmthin: local-lvm
 164         thinpool data
 165         vgname pve
 166         content rootdir,images
 167
 168 # default image store on ZFS based installation
 169 zfspool: local-zfs
 170         pool rpool/data
 171         sparse
 172         content images,rootdir
 173 ----
 174
 175
 176 Common Storage Properties
 177 ~~~~~~~~~~~~~~~~~~~~~~~~~
 178
 179 A few storage properties are common among different storage types.
 180
 181 nodes::
 182
 183 List of cluster node names where this storage is
 184 usable/accessible. One can use this property to restrict storage
 185 access to a limited set of nodes.
 186
 187 content::
 188
 189 A storage can support several content types, for example virtual disk
 190 images, cdrom iso images, container templates or container root
 191 directories. Not all storage types support all content types. One can set
 192 this property to select for what this storage is used for.
 193
 194 images:::
 195
 196 KVM-Qemu VM images.
 197
 198 rootdir:::
 199
 200 Allow to store container data.
 201
 202 vztmpl:::
 203
 204 Container templates.
 205
 206 backup:::
 207
 208 Backup files (`vzdump`).
 209
 210 iso:::
 211
 212 ISO images
 213
 214 shared::
 215
 216 Mark storage as shared.
 217
 218 disable::
 219
 220 You can use this flag to disable the storage completely.
 221
 222 maxfiles::
 223
 224 Maximum number of backup files per VM. Use `0` for unlimited.
 225
 226 format::
 227
 228 Default image format (`raw|qcow2|vmdk`)
 229
 230
 231 WARNING: It is not advisable to use the same storage pool on different
 232 {pve} clusters. Some storage operation need exclusive access to the
 233 storage, so proper locking is required. While this is implemented
 234 within a cluster, it does not work between different clusters.
 235
 236
 237 Volumes
 238 -------
 239
 240 We use a special notation to address storage data. When you allocate
 241 data from a storage pool, it returns such a volume identifier. A volume
 242 is identified by the `<STORAGE_ID>`, followed by a storage type
 243 dependent volume name, separated by colon. A valid `<VOLUME_ID>` looks
 244 like:
 245
 246  local:230/example-image.raw
 247
 248  local:iso/debian-501-amd64-netinst.iso
 249
 250  local:vztmpl/debian-5.0-joomla_1.5.9-1_i386.tar.gz
 251
 252  iscsi-storage:0.0.2.scsi-14f504e46494c4500494b5042546d2d646744372d31616d61
 253
 254 To get the file system path for a `<VOLUME_ID>` use:
 255
 256  pvesm path <VOLUME_ID>
 257
 258
 259 Volume Ownership
 260 ~~~~~~~~~~~~~~~~
 261
 262 There exists an ownership relation for `image` type volumes. Each such
 263 volume is owned by a VM or Container. For example volume
 264 `local:230/example-image.raw` is owned by VM 230. Most storage
 265 backends encodes this ownership information into the volume name.
 266
 267 When you remove a VM or Container, the system also removes all
 268 associated volumes which are owned by that VM or Container.
 269
 270
 271 Using the Command Line Interface
 272 --------------------------------
 273
 274 It is recommended to familiarize yourself with the concept behind storage
 275 pools and volume identifiers, but in real life, you are not forced to do any
 276 of those low level operations on the command line. Normally,
 277 allocation and removal of volumes is done by the VM and Container
 278 management tools.
 279
 280 Nevertheless, there is a command line tool called `pvesm` (``{pve}
 281 Storage Manager''), which is able to perform common storage management
 282 tasks.
 283
 284
 285 Examples
 286 ~~~~~~~~
 287
 288 Add storage pools
 289
 290  pvesm add <TYPE> <STORAGE_ID> <OPTIONS>
 291  pvesm add dir <STORAGE_ID> --path <PATH>
 292  pvesm add nfs <STORAGE_ID> --path <PATH> --server <SERVER> --export <EXPORT>
 293  pvesm add lvm <STORAGE_ID> --vgname <VGNAME>
 294  pvesm add iscsi <STORAGE_ID> --portal <HOST[:PORT]> --target <TARGET>
 295
 296 Disable storage pools
 297
 298  pvesm set <STORAGE_ID> --disable 1
 299
 300 Enable storage pools
 301
 302  pvesm set <STORAGE_ID> --disable 0
 303
 304 Change/set storage options
 305
 306  pvesm set <STORAGE_ID> <OPTIONS>
 307  pvesm set <STORAGE_ID> --shared 1
 308  pvesm set local --format qcow2
 309  pvesm set <STORAGE_ID> --content iso
 310
 311 Remove storage pools. This does not delete any data, and does not
 312 disconnect or unmount anything. It just removes the storage
 313 configuration.
 314
 315  pvesm remove <STORAGE_ID>
 316
 317 Allocate volumes
 318
 319  pvesm alloc <STORAGE_ID> <VMID> <name> <size> [--format <raw|qcow2>]
 320
 321 Allocate a 4G volume in local storage. The name is auto-generated if
 322 you pass an empty string as `<name>`
 323
 324  pvesm alloc local <VMID> '' 4G
 325
 326 Free volumes
 327
 328  pvesm free <VOLUME_ID>
 329
 330 WARNING: This really destroys all volume data.
 331
 332 List storage status
 333
 334  pvesm status
 335
 336 List storage contents
 337
 338  pvesm list <STORAGE_ID> [--vmid <VMID>]
 339
 340 List volumes allocated by VMID
 341
 342  pvesm list <STORAGE_ID> --vmid <VMID>
 343
 344 List iso images
 345
 346  pvesm list <STORAGE_ID> --iso
 347
 348 List container templates
 349
 350  pvesm list <STORAGE_ID> --vztmpl
 351
 352 Show file system path for a volume
 353
 354  pvesm path <VOLUME_ID>
 355
 356 ifdef::wiki[]
 357
 358 See Also
 359 --------
 360
 361 * link:/wiki/Storage:_Directory[Storage: Directory]
 362
 363 * link:/wiki/Storage:_GlusterFS[Storage: GlusterFS]
 364
 365 * link:/wiki/Storage:_User_Mode_iSCSI[Storage: User Mode iSCSI]
 366
 367 * link:/wiki/Storage:_iSCSI[Storage: iSCSI]
 368
 369 * link:/wiki/Storage:_LVM[Storage: LVM]
 370
 371 * link:/wiki/Storage:_LVM_Thin[Storage: LVM Thin]
 372
 373 * link:/wiki/Storage:_NFS[Storage: NFS]
 374
 375 * link:/wiki/Storage:_CIFS[Storage: CIFS]
 376
 377 * link:/wiki/Storage:_RBD[Storage: RBD]
 378
 379 * link:/wiki/Storage:_RBD[Storage: CephFS]
 380
 381 * link:/wiki/Storage:_ZFS[Storage: ZFS]
 382
 383 * link:/wiki/Storage:_ZFS_over_iSCSI[Storage: ZFS over iSCSI]
 384
 385 endif::wiki[]
 386
 387 ifndef::wiki[]
 388
 389 // backend documentation
 390
 391 include::pve-storage-dir.adoc[]
 392
 393 include::pve-storage-nfs.adoc[]
 394
 395 include::pve-storage-cifs.adoc[]
 396
 397 include::pve-storage-glusterfs.adoc[]
 398
 399 include::pve-storage-zfspool.adoc[]
 400
 401 include::pve-storage-lvm.adoc[]
 402
 403 include::pve-storage-lvmthin.adoc[]
 404
 405 include::pve-storage-iscsi.adoc[]
 406
 407 include::pve-storage-iscsidirect.adoc[]
 408
 409 include::pve-storage-rbd.adoc[]
 410
 411 include::pve-storage-cephfs.adoc[]
 412
 413
 414
 415 ifdef::manvolnum[]
 416 include::pve-copyright.adoc[]
 417 endif::manvolnum[]
 418
 419 endif::wiki[]
 420