pve-storage-lvmthin.adoc

   1 LVM thin Backend
   2 ----------------
   3 include::attributes.txt[]
   4
   5 Storage pool type: `lvmthin`
   6
   7 LVM normally allocates blocks when you create a volume. LVM thin pools
   8 instead allocates blocks when they are written. This behaviour is
   9 called thin-provisioning, because volumes can be much larger than
  10 physically available space.
  11
  12 You can use the normal LVM command line tools to manage and create LVM
  13 thin pools (see 'man lvmthin' for details). Assuming you already have
  14 a LVM volume group called `pve`, the following commands create a new
  15 LVM thin pool (size 100G) called `data`:
  16
  17 ----
  18 lvcreate -L 100G -n data pve
  19 lvconvert --type thin-pool pve/data
  20 ----
  21
  22
  23 Configuration
  24 ~~~~~~~~~~~~~
  25
  26 The LVM thin backend supports the common storage properties `content`, `nodes`,
  27 `disable`, and the following LVM specific properties:
  28
  29 `vgname`::
  30
  31 LVM volume group name. This must point to an existing volume group.
  32
  33 `thinpool`::
  34
  35 The name of the LVM thin pool.
  36
  37
  38 .Configuration Example ('/etc/pve/storage.cfg')
  39 ----
  40 lvmthin: local-lvm
  41         thinpool data
  42         vgname pve
  43         content rootdir,images
  44 ----
  45
  46
  47 File naming conventions
  48 ~~~~~~~~~~~~~~~~~~~~~~~
  49
  50 The backend use basically the same naming conventions as the ZFS pool
  51 backend.
  52
  53  vm-<VMID>-<NAME>      // normal VM images
  54
  55
  56 Storage Features
  57 ~~~~~~~~~~~~~~~~
  58
  59 LVM thin is a block storage, but fully supports snapshots and clones
  60 efficiently. New volumes are automatically initialized with zero.
  61
  62 It must be mentioned that LVM thin pools cannot be shared across
  63 multiple nodes, so you can only use them as local storage.
  64
  65 .Storage features for backend `lvmthin`
  66 [width="100%",cols="m,m,3*d",options="header"]
  67 |==============================================================================
  68 |Content types  |Image formats  |Shared   |Snapshots |Clones
  69 |images rootdir |raw            |no       |yes       |yes
  70 |==============================================================================
  71
  72 Examples
  73 ~~~~~~~~
  74
  75 List available LVM thin pools on volume group `pve`:
  76
  77  # pvesm lvmthinscan pve
  78
  79 ifdef::wiki[]
  80
  81 See Also
  82 ~~~~~~~~
  83
  84 * link:/index.php/Storage[Storage]
  85
  86 endif::wiki[]