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