pve-storage-lvmthin.adoc

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