pvesm.adoc

   1 [[chapter-storage]]
   2 ifdef::manvolnum[]
   3 PVE({manvolnum})
   4 ================
   5 include::attributes.txt[]
   6
   7 :pve-toplevel:
   8
   9 NAME
  10 ----
  11
  12 pvesm - Proxmox VE Storage Manager
  13
  14
  15 SYNOPSIS
  16 --------
  17
  18 include::pvesm.1-synopsis.adoc[]
  19
  20 DESCRIPTION
  21 -----------
  22 endif::manvolnum[]
  23
  24 ifndef::manvolnum[]
  25 {pve} Storage
  26 =============
  27 include::attributes.txt[]
  28 endif::manvolnum[]
  29
  30 ifdef::wiki[]
  31 :pve-toplevel:
  32 endif::wiki[]
  33
  34 The {pve} storage model is very flexible. Virtual machine images
  35 can either be stored on one or several local storages, or on shared
  36 storage like NFS or iSCSI (NAS, SAN). There are no limits, and you may
  37 configure as many storage pools as you like. You can use all
  38 storage technologies available for Debian Linux.
  39
  40 One major benefit of storing VMs on shared storage is the ability to
  41 live-migrate running machines without any downtime, as all nodes in
  42 the cluster have direct access to VM disk images. There is no need to
  43 copy VM image data, so live migration is very fast in that case.
  44
  45 The storage library (package `libpve-storage-perl`) uses a flexible
  46 plugin system to provide a common interface to all storage types. This
  47 can be easily adopted to include further storage types in future.
  48
  49
  50 Storage Types
  51 -------------
  52
  53 There are basically two different classes of storage types:
  54
  55 Block level storage::
  56
  57 Allows to store large 'raw' images. It is usually not possible to store
  58 other files (ISO, backups, ..) on such storage types. Most modern
  59 block level storage implementations support snapshots and clones.
  60 RADOS, Sheepdog and DRBD are distributed systems, replicating storage
  61 data to different nodes.
  62
  63 File level storage::
  64
  65 They allow access to a full featured (POSIX) file system. They are
  66 more flexible, and allows you to store any content type. ZFS is
  67 probably the most advanced system, and it has full support for
  68 snapshots and clones.
  69
  70
  71 .Available storage types
  72 [width="100%",cols="<d,1*m,4*d",options="header"]
  73 |===========================================================
  74 |Description    |PVE type    |Level |Shared|Snapshots|Stable
  75 |ZFS (local)    |zfspool     |file  |no    |yes      |yes
  76 |Directory      |dir         |file  |no    |no       |yes
  77 |NFS            |nfs         |file  |yes   |no       |yes
  78 |GlusterFS      |glusterfs   |file  |yes   |no       |yes
  79 |LVM            |lvm         |block |no    |no       |yes
  80 |LVM-thin       |lvmthin     |block |no    |yes      |yes
  81 |iSCSI/kernel   |iscsi       |block |yes   |no       |yes
  82 |iSCSI/libiscsi |iscsidirect |block |yes   |no       |yes
  83 |Ceph/RBD       |rbd         |block |yes   |yes      |yes
  84 |Sheepdog       |sheepdog    |block |yes   |yes      |beta
  85 |DRBD9          |drbd        |block |yes   |yes      |beta
  86 |ZFS over iSCSI |zfs         |block |yes   |yes      |yes
  87 |=========================================================
  88
  89 TIP: It is possible to use LVM on top of an iSCSI storage. That way
  90 you get a `shared` LVM storage.
  91
  92
  93 Thin Provisioning
  94 ~~~~~~~~~~~~~~~~~
  95
  96 A number of storages, and the Qemu image format `qcow2`, support 'thin
  97 provisioning'.  With thin provisioning activated, only the blocks that
  98 the guest system actually use will be written to the storage.
  99
 100 Say for instance you create a VM with a 32GB hard disk, and after
 101 installing the guest system OS, the root file system of the VM contains
 102 3 GB of data.  In that case only 3GB are written to the storage, even
 103 if the guest VM sees a 32GB hard drive. In this way thin provisioning
 104 allows you to create disk images which are larger than the currently
 105 available storage blocks. You can create large disk images for your
 106 VMs, and when the need arises, add more disks to your storage without
 107 resizing the VMs' file systems.
 108
 109 All storage types which have the ``Snapshots'' feature also support thin
 110 provisioning.
 111
 112 CAUTION: If a storage runs full, all guests using volumes on that
 113 storage receives IO error. This can cause file system inconsistencies
 114 and may corrupt your data. So it is advisable to avoid
 115 over-provisioning of your storage resources, or carefully observe
 116 free space to avoid such conditions.
 117
 118
 119 Storage Configuration
 120 ---------------------
 121
 122 All {pve} related storage configuration is stored within a single text
 123 file at `/etc/pve/storage.cfg`. As this file is within `/etc/pve/`, it
 124 gets automatically distributed to all cluster nodes. So all nodes
 125 share the same storage configuration.
 126
 127 Sharing storage configuration make perfect sense for shared storage,
 128 because the same ``shared'' storage is accessible from all nodes. But is
 129 also useful for local storage types. In this case such local storage
 130 is available on all nodes, but it is physically different and can have
 131 totally different content.
 132
 133
 134 Storage Pools
 135 ~~~~~~~~~~~~~
 136
 137 Each storage pool has a `<type>`, and is uniquely identified by its
 138 `<STORAGE_ID>`. A pool configuration looks like this:
 139
 140 ----
 141 <type>: <STORAGE_ID>
 142         <property> <value>
 143         <property> <value>
 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 have values, but some of
 149 them come with reasonable default. In that 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 for 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 shared::
 216
 217 Mark storage as shared.
 218
 219 disable::
 220
 221 You can use this flag to disable the storage completely.
 222
 223 maxfiles::
 224
 225 Maximum number of backup files per VM. Use `0` for unlimited.
 226
 227 format::
 228
 229 Default image format (`raw|qcow2|vmdk`)
 230
 231
 232 WARNING: It is not advisable to use the same storage pool on different
 233 {pve} clusters. Some storage operation need exclusive access to the
 234 storage, so proper locking is required. While this is implemented
 235 within a cluster, it does not work between different clusters.
 236
 237
 238 Volumes
 239 -------
 240
 241 We use a special notation to address storage data. When you allocate
 242 data from a storage pool, it returns such a volume identifier. A volume
 243 is identified by the `<STORAGE_ID>`, followed by a storage type
 244 dependent volume name, separated by colon. A valid `<VOLUME_ID>` looks
 245 like:
 246
 247  local:230/example-image.raw
 248
 249  local:iso/debian-501-amd64-netinst.iso
 250
 251  local:vztmpl/debian-5.0-joomla_1.5.9-1_i386.tar.gz
 252
 253  iscsi-storage:0.0.2.scsi-14f504e46494c4500494b5042546d2d646744372d31616d61
 254
 255 To get the file system path for a `<VOLUME_ID>` use:
 256
 257  pvesm path <VOLUME_ID>
 258
 259
 260 Volume Ownership
 261 ~~~~~~~~~~~~~~~~
 262
 263 There exists an ownership relation for `image` type volumes. Each such
 264 volume is owned by a VM or Container. For example volume
 265 `local:230/example-image.raw` is owned by VM 230. Most storage
 266 backends encodes this ownership information into the volume name.
 267
 268 When you remove a VM or Container, the system also removes all
 269 associated volumes which are owned by that VM or Container.
 270
 271
 272 Using the Command Line Interface
 273 --------------------------------
 274
 275 It is recommended to familiarize yourself with the concept behind storage
 276 pools and volume identifiers, but in real life, you are not forced to do any
 277 of those low level operations on the command line. Normally,
 278 allocation and removal of volumes is done by the VM and Container
 279 management tools.
 280
 281 Nevertheless, there is a command line tool called `pvesm` (``{pve}
 282 Storage Manager''), which is able to perform common storage management
 283 tasks.
 284
 285
 286 Examples
 287 ~~~~~~~~
 288
 289 Add storage pools
 290
 291  pvesm add <TYPE> <STORAGE_ID> <OPTIONS>
 292  pvesm add dir <STORAGE_ID> --path <PATH>
 293  pvesm add nfs <STORAGE_ID> --path <PATH> --server <SERVER> --export <EXPORT>
 294  pvesm add lvm <STORAGE_ID> --vgname <VGNAME>
 295  pvesm add iscsi <STORAGE_ID> --portal <HOST[:PORT]> --target <TARGET>
 296
 297 Disable storage pools
 298
 299  pvesm set <STORAGE_ID> --disable 1
 300
 301 Enable storage pools
 302
 303  pvesm set <STORAGE_ID> --disable 0
 304
 305 Change/set storage options
 306
 307  pvesm set <STORAGE_ID> <OPTIONS>
 308  pvesm set <STORAGE_ID> --shared 1
 309  pvesm set local --format qcow2
 310  pvesm set <STORAGE_ID> --content iso
 311
 312 Remove storage pools. This does not delete any data, and does not
 313 disconnect or unmount anything. It just removes the storage
 314 configuration.
 315
 316  pvesm remove <STORAGE_ID>
 317
 318 Allocate volumes
 319
 320  pvesm alloc <STORAGE_ID> <VMID> <name> <size> [--format <raw|qcow2>]
 321
 322 Allocate a 4G volume in local storage. The name is auto-generated if
 323 you pass an empty string as `<name>`
 324
 325  pvesm alloc local <VMID> '' 4G
 326
 327 Free volumes
 328
 329  pvesm free <VOLUME_ID>
 330
 331 WARNING: This really destroys all volume data.
 332
 333 List storage status
 334
 335  pvesm status
 336
 337 List storage contents
 338
 339  pvesm list <STORAGE_ID> [--vmid <VMID>]
 340
 341 List volumes allocated by VMID
 342
 343  pvesm list <STORAGE_ID> --vmid <VMID>
 344
 345 List iso images
 346
 347  pvesm list <STORAGE_ID> --iso
 348
 349 List container templates
 350
 351  pvesm list <STORAGE_ID> --vztmpl
 352
 353 Show file system path for a volume
 354
 355  pvesm path <VOLUME_ID>
 356
 357 ifdef::wiki[]
 358
 359 See Also
 360 --------
 361
 362 * link:/wiki/Storage:_Directory[Storage: Directory]
 363
 364 * link:/wiki/Storage:_GlusterFS[Storage: GlusterFS]
 365
 366 * link:/wiki/Storage:_User_Mode_iSCSI[Storage: User Mode iSCSI]
 367
 368 * link:/wiki/Storage:_iSCSI[Storage: iSCSI]
 369
 370 * link:/wiki/Storage:_LVM[Storage: LVM]
 371
 372 * link:/wiki/Storage:_LVM_Thin[Storage: LVM Thin]
 373
 374 * link:/wiki/Storage:_NFS[Storage: NFS]
 375
 376 * link:/wiki/Storage:_RBD[Storage: RBD]
 377
 378 * link:/wiki/Storage:_ZFS[Storage: ZFS]
 379
 380 * link:/wiki/Storage:_ZFS_over_iSCSI[Storage: ZFS over iSCSI]
 381
 382 endif::wiki[]
 383
 384 ifndef::wiki[]
 385
 386 // backend documentation
 387
 388 include::pve-storage-dir.adoc[]
 389
 390 include::pve-storage-nfs.adoc[]
 391
 392 include::pve-storage-glusterfs.adoc[]
 393
 394 include::pve-storage-zfspool.adoc[]
 395
 396 include::pve-storage-lvm.adoc[]
 397
 398 include::pve-storage-lvmthin.adoc[]
 399
 400 include::pve-storage-iscsi.adoc[]
 401
 402 include::pve-storage-iscsidirect.adoc[]
 403
 404 include::pve-storage-rbd.adoc[]
 405
 406
 407
 408 ifdef::manvolnum[]
 409 include::pve-copyright.adoc[]
 410 endif::manvolnum[]
 411
 412 endif::wiki[]
 413