mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2024-12-22 21:55:25 +00:00
49 lines
1.7 KiB
ReStructuredText
49 lines
1.7 KiB
ReStructuredText
|
=========
|
||
|
|
Snapshots
|
||
|
|
=========
|
||
|
|
|
||
|
|
.. contents::
|
||
|
|
|
||
|
|
Manual storage snapshotting
|
||
|
|
===========================
|
||
|
|
|
||
|
|
Certain use cases such as block storage on LVM or disks backed via storage
|
||
|
|
exported through the ``vhost-user-blk`` protocol may require that snapshots are
|
||
|
|
done in conjunction with the storage provider which is not managed by **libvirt**.
|
||
|
|
|
||
|
|
To achieve this such disks can use ``snapshot`` mode ``manual``. When a snapshot
|
||
|
|
has a disk in manual mode the following happens:
|
||
|
|
|
||
|
|
#. ``libvirt`` takes snapshot of the VM memory if requested
|
||
|
|
|
||
|
|
#. If a live snapshot is requested (``VIR_DOMAIN_SNAPSHOT_CREATE_LIVE``) the
|
||
|
|
VM runs until the memory snapshot phase completes and is then paused.
|
||
|
|
#. Otherwise the VM is paused right away.
|
||
|
|
|
||
|
|
#. Snapshot of disks which are marked for external snapsot is executed
|
||
|
|
#. The API return success, the VM is paused.
|
||
|
|
#. The user snapshots the externally managed storage
|
||
|
|
#. The user resumes the execution of the VM (``virsh resume $VM``)
|
||
|
|
|
||
|
|
Overview of manual snapshots
|
||
|
|
----------------------------
|
||
|
|
|
||
|
|
Manual snapshot of a disk is requested by setting the ``snapshot`` property to
|
||
|
|
``manual`` in the snapshot XML ::
|
||
|
|
|
||
|
|
<domainsnapshot>
|
||
|
|
<memory file='/path/to/memory/img'/>
|
||
|
|
<disks>
|
||
|
|
<disk name='vda' snapshot='manual'/>
|
||
|
|
<disk name='vdb' snapshot='external'/>
|
||
|
|
<disk name='vdc' snapshot='no'/>
|
||
|
|
</disks>
|
||
|
|
</domainsnapshot>
|
||
|
|
|
||
|
|
or ``--diskspec vda,snapshot=manual`` when using ``virsh snapshot-create-as``::
|
||
|
|
|
||
|
|
$ virsh snapshot-create-as --diskspec vda,snapshot=manual \
|
||
|
|
--diskspec vdb,snapshot=external \
|
||
|
|
--diskspec vdc,snapshot=no $VM \
|
||
|
|
--memspec file=/path/to/memory/img
|