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