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LVM thin Backend
----------------
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:title: Storage: LVM Thin
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Storage pool type: `lvmthin`

LVM normally allocates blocks when you create a volume. LVM thin pools
instead allocates blocks when they are written. This behaviour is
called thin-provisioning, because volumes can be much larger than
physically available space.

You can use the normal LVM command line tools to manage and create LVM
thin pools (see `man lvmthin` for details). Assuming you already have
a LVM volume group called `pve`, the following commands create a new
LVM thin pool (size 100G) called `data`:

----
lvcreate -L 100G -n data pve
lvconvert --type thin-pool pve/data
----


Configuration
~~~~~~~~~~~~~

The LVM thin backend supports the common storage properties `content`, `nodes`,
`disable`, and the following LVM specific properties:

`vgname`::

LVM volume group name. This must point to an existing volume group.

`thinpool`::

The name of the LVM thin pool.


.Configuration Example (`/etc/pve/storage.cfg`)
----
lvmthin: local-lvm
	thinpool data
	vgname pve
	content rootdir,images
----


File naming conventions
~~~~~~~~~~~~~~~~~~~~~~~

The backend use basically the same naming conventions as the ZFS pool
backend.

 vm-<VMID>-<NAME>      // normal VM images


Storage Features
~~~~~~~~~~~~~~~~

LVM thin is a block storage, but fully supports snapshots and clones
efficiently. New volumes are automatically initialized with zero.

It must be mentioned that LVM thin pools cannot be shared across
multiple nodes, so you can only use them as local storage.

.Storage features for backend `lvmthin`
[width="100%",cols="m,m,3*d",options="header"]
|==============================================================================
|Content types  |Image formats  |Shared   |Snapshots |Clones
|images rootdir |raw            |no       |yes       |yes
|==============================================================================

Examples
~~~~~~~~

List available LVM thin pools on volume group `pve`:

 # pvesm lvmthinscan pve

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See Also
~~~~~~~~

* link:/wiki/Storage[Storage]

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