pve-storage-lvmthin.adoc

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