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