pvesm.adoc

   1 [[chapter-storage]]
   2 ifdef::manvolnum[]
   3 PVE({manvolnum})
   4 ================
   5 include::attributes.txt[]
   6
   7 NAME
   8 ----
   9
  10 pvesm - Proxmox VE Storage Manager
  11
  12
  13 SYNOPSYS
  14 --------
  15
  16 include::pvesm.1-synopsis.adoc[]
  17
  18 DESCRIPTION
  19 -----------
  20 endif::manvolnum[]
  21
  22 ifndef::manvolnum[]
  23 {pve} Storage
  24 =============
  25 include::attributes.txt[]
  26 endif::manvolnum[]
  27
  28 The {pve} storage model is very flexible. Virtual machine images
  29 can either be stored on one or several local storages, or on shared
  30 storage like NFS or iSCSI (NAS, SAN). There are no limits, and you may
  31 configure as many storage pools as you like. You can use all
  32 storage technologies available for Debian Linux.
  33
  34 One major benefit of storing VMs on shared storage is the ability to
  35 live-migrate running machines without any downtime, as all nodes in
  36 the cluster have direct access to VM disk images. There is no need to
  37 copy VM image data, so live migration is very fast in that case.
  38
  39 The storage library (package `libpve-storage-perl`) uses a flexible
  40 plugin system to provide a common interface to all storage types. This
  41 can be easily adopted to include further storage types in future.
  42
  43
  44 Storage Types
  45 -------------
  46
  47 There are basically two different classes of storage types:
  48
  49 Block level storage::
  50
  51 Allows to store large 'raw' images. It is usually not possible to store
  52 other files (ISO, backups, ..) on such storage types. Most modern
  53 block level storage implementations support snapshots and clones.
  54 RADOS, Sheepdog and DRBD are distributed systems, replicating storage
  55 data to different nodes.
  56
  57 File level storage::
  58
  59 They allow access to a full featured (POSIX) file system. They are
  60 more flexible, and allows you to store any content type. ZFS is
  61 probably the most advanced system, and it has full support for
  62 snapshots and clones.
  63
  64
  65 .Available storage types
  66 [width="100%",cols="<d,1*m,4*d",options="header"]
  67 |===========================================================
  68 |Description    |PVE type    |Level |Shared|Snapshots|Stable
  69 |ZFS (local)    |zfspool     |file  |no    |yes      |yes
  70 |Directory      |dir         |file  |no    |no       |yes
  71 |NFS            |nfs         |file  |yes   |no       |yes
  72 |GlusterFS      |glusterfs   |file  |yes   |no       |yes
  73 |LVM            |lvm         |block |no    |no       |yes
  74 |LVM-thin       |lvmthin     |block |no    |yes      |yes
  75 |iSCSI/kernel   |iscsi       |block |yes   |no       |yes
  76 |iSCSI/libiscsi |iscsidirect |block |yes   |no       |yes
  77 |Ceph/RBD       |rbd         |block |yes   |yes      |yes
  78 |Sheepdog       |sheepdog    |block |yes   |yes      |beta
  79 |DRBD9          |drbd        |block |yes   |yes      |beta
  80 |ZFS over iSCSI |zfs         |block |yes   |yes      |yes
  81 |=========================================================
  82
  83 TIP: It is possible to use LVM on top of an iSCSI storage. That way
  84 you get a `shared` LVM storage.
  85
  86
  87 Thin Provisioning
  88 ~~~~~~~~~~~~~~~~~
  89
  90 A number of storages, and the Qemu image format `qcow2`, support 'thin
  91 provisioning'.  With thin provisioning activated, only the blocks that
  92 the guest system actually use will be written to the storage.
  93
  94 Say for instance you create a VM with a 32GB hard disk, and after
  95 installing the guest system OS, the root file system of the VM contains
  96 3 GB of data.  In that case only 3GB are written to the storage, even
  97 if the guest VM sees a 32GB hard drive. In this way thin provisioning
  98 allows you to create disk images which are larger than the currently
  99 available storage blocks. You can create large disk images for your
 100 VMs, and when the need arises, add more disks to your storage without
 101 resizing the VMs' file systems.
 102
 103 All storage types which have the ``Snapshots'' feature also support thin
 104 provisioning.
 105
 106 CAUTION: If a storage runs full, all guests using volumes on that
 107 storage receives IO error. This can cause file system inconsistencies
 108 and may corrupt your data. So it is advisable to avoid
 109 over-provisioning of your storage resources, or carefully observe
 110 free space to avoid such conditions.
 111
 112
 113 Storage Configuration
 114 ---------------------
 115
 116 All {pve} related storage configuration is stored within a single text
 117 file at `/etc/pve/storage.cfg`. As this file is within `/etc/pve/`, it
 118 gets automatically distributed to all cluster nodes. So all nodes
 119 share the same storage configuration.
 120
 121 Sharing storage configuration make perfect sense for shared storage,
 122 because the same ``shared'' storage is accessible from all nodes. But is
 123 also useful for local storage types. In this case such local storage
 124 is available on all nodes, but it is physically different and can have
 125 totally different content.
 126
 127
 128 Storage Pools
 129 ~~~~~~~~~~~~~
 130
 131 Each storage pool has a `<type>`, and is uniquely identified by its
 132 `<STORAGE_ID>`. A pool configuration looks like this:
 133
 134 ----
 135 <type>: <STORAGE_ID>
 136         <property> <value>
 137         <property> <value>
 138         ...
 139 ----
 140
 141 The `<type>: <STORAGE_ID>` line starts the pool definition, which is then
 142 followed by a list of properties. Most properties have values, but some of
 143 them come with reasonable default. In that case you can omit the value.
 144
 145 To be more specific, take a look at the default storage configuration
 146 after installation. It contains one special local storage pool named
 147 `local`, which refers to the directory `/var/lib/vz` and is always
 148 available. The {pve} installer creates additional storage entries
 149 depending on the storage type chosen at installation time.
 150
 151 .Default storage configuration (`/etc/pve/storage.cfg`)
 152 ----
 153 dir: local
 154         path /var/lib/vz
 155         content iso,vztmpl,backup
 156
 157 # default image store on LVM based installation
 158 lvmthin: local-lvm
 159         thinpool data
 160         vgname pve
 161         content rootdir,images
 162
 163 # default image store on ZFS based installation
 164 zfspool: local-zfs
 165         pool rpool/data
 166         sparse
 167         content images,rootdir
 168 ----
 169
 170
 171 Common Storage Properties
 172 ~~~~~~~~~~~~~~~~~~~~~~~~~
 173
 174 A few storage properties are common among different storage types.
 175
 176 nodes::
 177
 178 List of cluster node names where this storage is
 179 usable/accessible. One can use this property to restrict storage
 180 access to a limited set of nodes.
 181
 182 content::
 183
 184 A storage can support several content types, for example virtual disk
 185 images, cdrom iso images, container templates or container root
 186 directories. Not all storage types support all content types. One can set
 187 this property to select for what this storage is used for.
 188
 189 images:::
 190
 191 KVM-Qemu VM images.
 192
 193 rootdir:::
 194
 195 Allow to store container data.
 196
 197 vztmpl:::
 198
 199 Container templates.
 200
 201 backup:::
 202
 203 Backup files (`vzdump`).
 204
 205 iso:::
 206
 207 ISO images
 208
 209 shared::
 210
 211 Mark storage as shared.
 212
 213 disable::
 214
 215 You can use this flag to disable the storage completely.
 216
 217 maxfiles::
 218
 219 Maximum number of backup files per VM. Use `0` for unlimited.
 220
 221 format::
 222
 223 Default image format (`raw|qcow2|vmdk`)
 224
 225
 226 WARNING: It is not advisable to use the same storage pool on different
 227 {pve} clusters. Some storage operation need exclusive access to the
 228 storage, so proper locking is required. While this is implemented
 229 within a cluster, it does not work between different clusters.
 230
 231
 232 Volumes
 233 -------
 234
 235 We use a special notation to address storage data. When you allocate
 236 data from a storage pool, it returns such a volume identifier. A volume
 237 is identified by the `<STORAGE_ID>`, followed by a storage type
 238 dependent volume name, separated by colon. A valid `<VOLUME_ID>` looks
 239 like:
 240
 241  local:230/example-image.raw
 242
 243  local:iso/debian-501-amd64-netinst.iso
 244
 245  local:vztmpl/debian-5.0-joomla_1.5.9-1_i386.tar.gz
 246
 247  iscsi-storage:0.0.2.scsi-14f504e46494c4500494b5042546d2d646744372d31616d61
 248
 249 To get the file system path for a `<VOLUME_ID>` use:
 250
 251  pvesm path <VOLUME_ID>
 252
 253
 254 Volume Ownership
 255 ~~~~~~~~~~~~~~~~
 256
 257 There exists an ownership relation for `image` type volumes. Each such
 258 volume is owned by a VM or Container. For example volume
 259 `local:230/example-image.raw` is owned by VM 230. Most storage
 260 backends encodes this ownership information into the volume name.
 261
 262 When you remove a VM or Container, the system also removes all
 263 associated volumes which are owned by that VM or Container.
 264
 265
 266 Using the Command Line Interface
 267 --------------------------------
 268
 269 It is recommended to familiarize yourself with the concept behind storage
 270 pools and volume identifiers, but in real life, you are not forced to do any
 271 of those low level operations on the command line. Normally,
 272 allocation and removal of volumes is done by the VM and Container
 273 management tools.
 274
 275 Nevertheless, there is a command line tool called `pvesm` (``{pve}
 276 Storage Manager''), which is able to perform common storage management
 277 tasks.
 278
 279
 280 Examples
 281 ~~~~~~~~
 282
 283 Add storage pools
 284
 285  pvesm add <TYPE> <STORAGE_ID> <OPTIONS>
 286  pvesm add dir <STORAGE_ID> --path <PATH>
 287  pvesm add nfs <STORAGE_ID> --path <PATH> --server <SERVER> --export <EXPORT>
 288  pvesm add lvm <STORAGE_ID> --vgname <VGNAME>
 289  pvesm add iscsi <STORAGE_ID> --portal <HOST[:PORT]> --target <TARGET>
 290
 291 Disable storage pools
 292
 293  pvesm set <STORAGE_ID> --disable 1
 294
 295 Enable storage pools
 296
 297  pvesm set <STORAGE_ID> --disable 0
 298
 299 Change/set storage options
 300
 301  pvesm set <STORAGE_ID> <OPTIONS>
 302  pvesm set <STORAGE_ID> --shared 1
 303  pvesm set local --format qcow2
 304  pvesm set <STORAGE_ID> --content iso
 305
 306 Remove storage pools. This does not delete any data, and does not
 307 disconnect or unmount anything. It just removes the storage
 308 configuration.
 309
 310  pvesm remove <STORAGE_ID>
 311
 312 Allocate volumes
 313
 314  pvesm alloc <STORAGE_ID> <VMID> <name> <size> [--format <raw|qcow2>]
 315
 316 Allocate a 4G volume in local storage. The name is auto-generated if
 317 you pass an empty string as `<name>`
 318
 319  pvesm alloc local <VMID> '' 4G
 320
 321 Free volumes
 322
 323  pvesm free <VOLUME_ID>
 324
 325 WARNING: This really destroys all volume data.
 326
 327 List storage status
 328
 329  pvesm status
 330
 331 List storage contents
 332
 333  pvesm list <STORAGE_ID> [--vmid <VMID>]
 334
 335 List volumes allocated by VMID
 336
 337  pvesm list <STORAGE_ID> --vmid <VMID>
 338
 339 List iso images
 340
 341  pvesm list <STORAGE_ID> --iso
 342
 343 List container templates
 344
 345  pvesm list <STORAGE_ID> --vztmpl
 346
 347 Show file system path for a volume
 348
 349  pvesm path <VOLUME_ID>
 350
 351 ifdef::wiki[]
 352
 353 See Also
 354 --------
 355
 356 * link:/wiki/Storage:_Directory[Storage: Directory]
 357
 358 * link:/wiki/Storage:_GlusterFS[Storage: GlusterFS]
 359
 360 * link:/wiki/Storage:_User_Mode_iSCSI[Storage: User Mode iSCSI]
 361
 362 * link:/wiki/Storage:_iSCSI[Storage: iSCSI]
 363
 364 * link:/wiki/Storage:_LVM[Storage: LVM]
 365
 366 * link:/wiki/Storage:_LVM_Thin[Storage: LVM Thin]
 367
 368 * link:/wiki/Storage:_NFS[Storage: NFS]
 369
 370 * link:/wiki/Storage:_RBD[Storage: RBD]
 371
 372 * link:/wiki/Storage:_ZFS[Storage: ZFS]
 373
 374 * link:/wiki/Storage:_ZFS_over_iSCSI[Storage: ZFS over iSCSI]
 375
 376 endif::wiki[]
 377
 378 ifndef::wiki[]
 379
 380 // backend documentation
 381
 382 include::pve-storage-dir.adoc[]
 383
 384 include::pve-storage-nfs.adoc[]
 385
 386 include::pve-storage-glusterfs.adoc[]
 387
 388 include::pve-storage-zfspool.adoc[]
 389
 390 include::pve-storage-lvm.adoc[]
 391
 392 include::pve-storage-lvmthin.adoc[]
 393
 394 include::pve-storage-iscsi.adoc[]
 395
 396 include::pve-storage-iscsidirect.adoc[]
 397
 398 include::pve-storage-rbd.adoc[]
 399
 400
 401
 402 ifdef::manvolnum[]
 403 include::pve-copyright.adoc[]
 404 endif::manvolnum[]
 405
 406 endif::wiki[]
 407