pve-storage-lvmthin.adoc

   1 LVM thin Backend
   2 ----------------
   3 include::attributes.txt[]
   4
   5 ifdef::wiki[]
   6 :pve-toplevel:
   7 :title: Storage: LVM Thin
   8 endif::wiki[]
   9
  10 Storage pool type: `lvmthin`
  11
  12 LVM normally allocates blocks when you create a volume. LVM thin pools
  13 instead allocates blocks when they are written. This behaviour is
  14 called thin-provisioning, because volumes can be much larger than
  15 physically available space.
  16
  17 You can use the normal LVM command line tools to manage and create LVM
  18 thin pools (see `man lvmthin` for details). Assuming you already have
  19 a LVM volume group called `pve`, the following commands create a new
  20 LVM thin pool (size 100G) called `data`:
  21
  22 ----
  23 lvcreate -L 100G -n data pve
  24 lvconvert --type thin-pool pve/data
  25 ----
  26
  27
  28 Configuration
  29 ~~~~~~~~~~~~~
  30
  31 The LVM thin backend supports the common storage properties `content`, `nodes`,
  32 `disable`, and the following LVM specific properties:
  33
  34 `vgname`::
  35
  36 LVM volume group name. This must point to an existing volume group.
  37
  38 `thinpool`::
  39
  40 The name of the LVM thin pool.
  41
  42
  43 .Configuration Example (`/etc/pve/storage.cfg`)
  44 ----
  45 lvmthin: local-lvm
  46         thinpool data
  47         vgname pve
  48         content rootdir,images
  49 ----
  50
  51
  52 File naming conventions
  53 ~~~~~~~~~~~~~~~~~~~~~~~
  54
  55 The backend use basically the same naming conventions as the ZFS pool
  56 backend.
  57
  58  vm-<VMID>-<NAME>      // normal VM images
  59
  60
  61 Storage Features
  62 ~~~~~~~~~~~~~~~~
  63
  64 LVM thin is a block storage, but fully supports snapshots and clones
  65 efficiently. New volumes are automatically initialized with zero.
  66
  67 It must be mentioned that LVM thin pools cannot be shared across
  68 multiple nodes, so you can only use them as local storage.
  69
  70 .Storage features for backend `lvmthin`
  71 [width="100%",cols="m,m,3*d",options="header"]
  72 |==============================================================================
  73 |Content types  |Image formats  |Shared   |Snapshots |Clones
  74 |images rootdir |raw            |no       |yes       |yes
  75 |==============================================================================
  76
  77 Examples
  78 ~~~~~~~~
  79
  80 List available LVM thin pools on volume group `pve`:
  81
  82  # pvesm lvmthinscan pve
  83
  84 ifdef::wiki[]
  85
  86 See Also
  87 ~~~~~~~~
  88
  89 * link:/wiki/Storage[Storage]
  90
  91 endif::wiki[]