pve-storage-lvmthin.adoc

   1 LVM thin Backend
   2 ----------------
   3 ifdef::wiki[]
   4 :pve-toplevel:
   5 :title: Storage: LVM Thin
   6 endif::wiki[]
   7
   8 Storage pool type: `lvmthin`
   9
  10 LVM normally allocates blocks when you create a volume. LVM thin pools
  11 instead allocates blocks when they are written. This behaviour is
  12 called thin-provisioning, because volumes can be much larger than
  13 physically available space.
  14
  15 You can use the normal LVM command line tools to manage and create LVM
  16 thin pools (see `man lvmthin` for details). Assuming you already have
  17 a LVM volume group called `pve`, the following commands create a new
  18 LVM thin pool (size 100G) called `data`:
  19
  20 ----
  21 lvcreate -L 100G -n data pve
  22 lvconvert --type thin-pool pve/data
  23 ----
  24
  25
  26 Configuration
  27 ~~~~~~~~~~~~~
  28
  29 The LVM thin backend supports the common storage properties `content`, `nodes`,
  30 `disable`, and the following LVM specific properties:
  31
  32 `vgname`::
  33
  34 LVM volume group name. This must point to an existing volume group.
  35
  36 `thinpool`::
  37
  38 The name of the LVM thin pool.
  39
  40
  41 .Configuration Example (`/etc/pve/storage.cfg`)
  42 ----
  43 lvmthin: local-lvm
  44         thinpool data
  45         vgname pve
  46         content rootdir,images
  47 ----
  48
  49
  50 File naming conventions
  51 ~~~~~~~~~~~~~~~~~~~~~~~
  52
  53 The backend use basically the same naming conventions as the ZFS pool
  54 backend.
  55
  56  vm-<VMID>-<NAME>      // normal VM images
  57
  58
  59 Storage Features
  60 ~~~~~~~~~~~~~~~~
  61
  62 LVM thin is a block storage, but fully supports snapshots and clones
  63 efficiently. New volumes are automatically initialized with zero.
  64
  65 It must be mentioned that LVM thin pools cannot be shared across
  66 multiple nodes, so you can only use them as local storage.
  67
  68 .Storage features for backend `lvmthin`
  69 [width="100%",cols="m,m,3*d",options="header"]
  70 |==============================================================================
  71 |Content types  |Image formats  |Shared   |Snapshots |Clones
  72 |images rootdir |raw            |no       |yes       |yes
  73 |==============================================================================
  74
  75 Examples
  76 ~~~~~~~~
  77
  78 List available LVM thin pools on volume group `pve`:
  79
  80  # pvesm lvmthinscan pve
  81
  82 ifdef::wiki[]
  83
  84 See Also
  85 ~~~~~~~~
  86
  87 * link:/wiki/Storage[Storage]
  88
  89 endif::wiki[]