Linux KVM Virtualization Manual Low-Level Guest Export/Import Procedure: Difference between revisions

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This is the procedure to [[Linux_Virtualization_Concepts#KVM_Virtual_Machine_Snapshot|snapshot a KVM virtual machine]]. It consists in taking snapshots of its XML definition and performing snapshots of all its storage devices.
This is the procedure to [[Linux_Virtualization_Concepts#KVM_Virtual_Machine_Snapshot|snapshot a KVM virtual machine]]. It consists in taking snapshots of its XML definition and performing snapshots of all its storage devices.


=Create a Snapshot Image=
=Take a Virtual Machine Snapshot=


{{Warn|If the virtual machine has more than one storage device attached, they all must be snapshot at the same time to produce a consistent snapshot that can be reverted to.}}
{{Warn|If the virtual machine has more than one storage device attached, they all must be snapshot at the same time to produce a consistent snapshot that can be reverted to.}}


==Procedure==
==Shutdown the Target Guest==
 
===Shutdown the Target Guest===


  [[virsh shutdown]] ''<vm-name>''
  [[virsh shutdown]] ''<vm-name>''


===Identify all Storage Devices===
==Identify all Storage Devices==


  [[virsh dumpxml]] ''<vm-name>''
  [[virsh dumpxml]] ''<vm-name>''
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  </disk>
  </disk>


===Snapshot Each Storage Device===
==Snapshot Each Storage Device==


  qemu-img snapshot -c <snapshot-tag> <volume-name>
  qemu-img snapshot -c <snapshot-tag> <volume-name>

Revision as of 17:57, 4 July 2017

Internal

Overview

This is the procedure to snapshot a KVM virtual machine. It consists in taking snapshots of its XML definition and performing snapshots of all its storage devices.

Take a Virtual Machine Snapshot


If the virtual machine has more than one storage device attached, they all must be snapshot at the same time to produce a consistent snapshot that can be reverted to.

Shutdown the Target Guest

virsh shutdown <vm-name>

Identify all Storage Devices

virsh dumpxml <vm-name>

Look for <disk> definitions. The disk definition specifies the source and the format of the virtual storage device. Example:

<disk type='file' device='disk'>
    <driver name='qemu' type='qcow2'/>
    <source file='/main-storage-pool/appproxy.qcow2'/>
    ...
</disk>

Snapshot Each Storage Device

qemu-img snapshot -c <snapshot-tag> <volume-name>

For more details about snapshot mechanics, see

qemu-img snapshot -c

Restore from Snapshot

Perform the steps described in the "" section in reverse order.

Alternative

Alternative suing qemu-img create. See

http://dustymabe.com/2015/01/11/qemu-img-backing-files-a-poor-mans-snapshotrollback/