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 DRBD 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 |DRBD9          |drbd        |block |yes   |yes      |beta
  82 |ZFS over iSCSI |zfs         |block |yes   |yes      |yes
  83 |=========================================================
  84
  85 TIP: It is possible to use LVM on top of an iSCSI storage. That way
  86 you get a `shared` LVM storage.
  87
  88
  89 Thin Provisioning
  90 ~~~~~~~~~~~~~~~~~
  91
  92 A number of storages, and the Qemu image format `qcow2`, support 'thin
  93 provisioning'.  With thin provisioning activated, only the blocks that
  94 the guest system actually use will be written to the storage.
  95
  96 Say for instance you create a VM with a 32GB hard disk, and after
  97 installing the guest system OS, the root file system of the VM contains
  98 3 GB of data.  In that case only 3GB are written to the storage, even
  99 if the guest VM sees a 32GB hard drive. In this way thin provisioning
 100 allows you to create disk images which are larger than the currently
 101 available storage blocks. You can create large disk images for your
 102 VMs, and when the need arises, add more disks to your storage without
 103 resizing the VMs' file systems.
 104
 105 All storage types which have the ``Snapshots'' feature also support thin
 106 provisioning.
 107
 108 CAUTION: If a storage runs full, all guests using volumes on that
 109 storage receives IO error. This can cause file system inconsistencies
 110 and may corrupt your data. So it is advisable to avoid
 111 over-provisioning of your storage resources, or carefully observe
 112 free space to avoid such conditions.
 113
 114
 115 Storage Configuration
 116 ---------------------
 117
 118 All {pve} related storage configuration is stored within a single text
 119 file at `/etc/pve/storage.cfg`. As this file is within `/etc/pve/`, it
 120 gets automatically distributed to all cluster nodes. So all nodes
 121 share the same storage configuration.
 122
 123 Sharing storage configuration make perfect sense for shared storage,
 124 because the same ``shared'' storage is accessible from all nodes. But is
 125 also useful for local storage types. In this case such local storage
 126 is available on all nodes, but it is physically different and can have
 127 totally different content.
 128
 129
 130 Storage Pools
 131 ~~~~~~~~~~~~~
 132
 133 Each storage pool has a `<type>`, and is uniquely identified by its
 134 `<STORAGE_ID>`. A pool configuration looks like this:
 135
 136 ----
 137 <type>: <STORAGE_ID>
 138         <property> <value>
 139         <property> <value>
 140         ...
 141 ----
 142
 143 The `<type>: <STORAGE_ID>` line starts the pool definition, which is then
 144 followed by a list of properties. Most properties have values, but some of
 145 them come with reasonable default. In that case you can omit the value.
 146
 147 To be more specific, take a look at the default storage configuration
 148 after installation. It contains one special local storage pool named
 149 `local`, which refers to the directory `/var/lib/vz` and is always
 150 available. The {pve} installer creates additional storage entries
 151 depending on the storage type chosen at installation time.
 152
 153 .Default storage configuration (`/etc/pve/storage.cfg`)
 154 ----
 155 dir: local
 156         path /var/lib/vz
 157         content iso,vztmpl,backup
 158
 159 # default image store on LVM based installation
 160 lvmthin: local-lvm
 161         thinpool data
 162         vgname pve
 163         content rootdir,images
 164
 165 # default image store on ZFS based installation
 166 zfspool: local-zfs
 167         pool rpool/data
 168         sparse
 169         content images,rootdir
 170 ----
 171
 172
 173 Common Storage Properties
 174 ~~~~~~~~~~~~~~~~~~~~~~~~~
 175
 176 A few storage properties are common among different storage types.
 177
 178 nodes::
 179
 180 List of cluster node names where this storage is
 181 usable/accessible. One can use this property to restrict storage
 182 access to a limited set of nodes.
 183
 184 content::
 185
 186 A storage can support several content types, for example virtual disk
 187 images, cdrom iso images, container templates or container root
 188 directories. Not all storage types support all content types. One can set
 189 this property to select for what this storage is used for.
 190
 191 images:::
 192
 193 KVM-Qemu VM images.
 194
 195 rootdir:::
 196
 197 Allow to store container data.
 198
 199 vztmpl:::
 200
 201 Container templates.
 202
 203 backup:::
 204
 205 Backup files (`vzdump`).
 206
 207 iso:::
 208
 209 ISO images
 210
 211 shared::
 212
 213 Mark storage as shared.
 214
 215 disable::
 216
 217 You can use this flag to disable the storage completely.
 218
 219 maxfiles::
 220
 221 Maximum number of backup files per VM. Use `0` for unlimited.
 222
 223 format::
 224
 225 Default image format (`raw|qcow2|vmdk`)
 226
 227
 228 WARNING: It is not advisable to use the same storage pool on different
 229 {pve} clusters. Some storage operation need exclusive access to the
 230 storage, so proper locking is required. While this is implemented
 231 within a cluster, it does not work between different clusters.
 232
 233
 234 Volumes
 235 -------
 236
 237 We use a special notation to address storage data. When you allocate
 238 data from a storage pool, it returns such a volume identifier. A volume
 239 is identified by the `<STORAGE_ID>`, followed by a storage type
 240 dependent volume name, separated by colon. A valid `<VOLUME_ID>` looks
 241 like:
 242
 243  local:230/example-image.raw
 244
 245  local:iso/debian-501-amd64-netinst.iso
 246
 247  local:vztmpl/debian-5.0-joomla_1.5.9-1_i386.tar.gz
 248
 249  iscsi-storage:0.0.2.scsi-14f504e46494c4500494b5042546d2d646744372d31616d61
 250
 251 To get the file system path for a `<VOLUME_ID>` use:
 252
 253  pvesm path <VOLUME_ID>
 254
 255
 256 Volume Ownership
 257 ~~~~~~~~~~~~~~~~
 258
 259 There exists an ownership relation for `image` type volumes. Each such
 260 volume is owned by a VM or Container. For example volume
 261 `local:230/example-image.raw` is owned by VM 230. Most storage
 262 backends encodes this ownership information into the volume name.
 263
 264 When you remove a VM or Container, the system also removes all
 265 associated volumes which are owned by that VM or Container.
 266
 267
 268 Using the Command Line Interface
 269 --------------------------------
 270
 271 It is recommended to familiarize yourself with the concept behind storage
 272 pools and volume identifiers, but in real life, you are not forced to do any
 273 of those low level operations on the command line. Normally,
 274 allocation and removal of volumes is done by the VM and Container
 275 management tools.
 276
 277 Nevertheless, there is a command line tool called `pvesm` (``{pve}
 278 Storage Manager''), which is able to perform common storage management
 279 tasks.
 280
 281
 282 Examples
 283 ~~~~~~~~
 284
 285 Add storage pools
 286
 287  pvesm add <TYPE> <STORAGE_ID> <OPTIONS>
 288  pvesm add dir <STORAGE_ID> --path <PATH>
 289  pvesm add nfs <STORAGE_ID> --path <PATH> --server <SERVER> --export <EXPORT>
 290  pvesm add lvm <STORAGE_ID> --vgname <VGNAME>
 291  pvesm add iscsi <STORAGE_ID> --portal <HOST[:PORT]> --target <TARGET>
 292
 293 Disable storage pools
 294
 295  pvesm set <STORAGE_ID> --disable 1
 296
 297 Enable storage pools
 298
 299  pvesm set <STORAGE_ID> --disable 0
 300
 301 Change/set storage options
 302
 303  pvesm set <STORAGE_ID> <OPTIONS>
 304  pvesm set <STORAGE_ID> --shared 1
 305  pvesm set local --format qcow2
 306  pvesm set <STORAGE_ID> --content iso
 307
 308 Remove storage pools. This does not delete any data, and does not
 309 disconnect or unmount anything. It just removes the storage
 310 configuration.
 311
 312  pvesm remove <STORAGE_ID>
 313
 314 Allocate volumes
 315
 316  pvesm alloc <STORAGE_ID> <VMID> <name> <size> [--format <raw|qcow2>]
 317
 318 Allocate a 4G volume in local storage. The name is auto-generated if
 319 you pass an empty string as `<name>`
 320
 321  pvesm alloc local <VMID> '' 4G
 322
 323 Free volumes
 324
 325  pvesm free <VOLUME_ID>
 326
 327 WARNING: This really destroys all volume data.
 328
 329 List storage status
 330
 331  pvesm status
 332
 333 List storage contents
 334
 335  pvesm list <STORAGE_ID> [--vmid <VMID>]
 336
 337 List volumes allocated by VMID
 338
 339  pvesm list <STORAGE_ID> --vmid <VMID>
 340
 341 List iso images
 342
 343  pvesm list <STORAGE_ID> --iso
 344
 345 List container templates
 346
 347  pvesm list <STORAGE_ID> --vztmpl
 348
 349 Show file system path for a volume
 350
 351  pvesm path <VOLUME_ID>
 352
 353 ifdef::wiki[]
 354
 355 See Also
 356 --------
 357
 358 * link:/wiki/Storage:_Directory[Storage: Directory]
 359
 360 * link:/wiki/Storage:_GlusterFS[Storage: GlusterFS]
 361
 362 * link:/wiki/Storage:_User_Mode_iSCSI[Storage: User Mode iSCSI]
 363
 364 * link:/wiki/Storage:_iSCSI[Storage: iSCSI]
 365
 366 * link:/wiki/Storage:_LVM[Storage: LVM]
 367
 368 * link:/wiki/Storage:_LVM_Thin[Storage: LVM Thin]
 369
 370 * link:/wiki/Storage:_NFS[Storage: NFS]
 371
 372 * link:/wiki/Storage:_RBD[Storage: RBD]
 373
 374 * link:/wiki/Storage:_ZFS[Storage: ZFS]
 375
 376 * link:/wiki/Storage:_ZFS_over_iSCSI[Storage: ZFS over iSCSI]
 377
 378 endif::wiki[]
 379
 380 ifndef::wiki[]
 381
 382 // backend documentation
 383
 384 include::pve-storage-dir.adoc[]
 385
 386 include::pve-storage-nfs.adoc[]
 387
 388 include::pve-storage-glusterfs.adoc[]
 389
 390 include::pve-storage-zfspool.adoc[]
 391
 392 include::pve-storage-lvm.adoc[]
 393
 394 include::pve-storage-lvmthin.adoc[]
 395
 396 include::pve-storage-iscsi.adoc[]
 397
 398 include::pve-storage-iscsidirect.adoc[]
 399
 400 include::pve-storage-rbd.adoc[]
 401
 402
 403
 404 ifdef::manvolnum[]
 405 include::pve-copyright.adoc[]
 406 endif::manvolnum[]
 407
 408 endif::wiki[]
 409