Difference between revisions of "Virsh snapshot-create-as"

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: <code>--atomic</code> Libvirt will guarantee that the snapshot either succeeds, or fails with no changes.<ref>https://blog.devzero.be/post/kvm-live-vm-backup/</ref>
 
: <code>--atomic</code> Libvirt will guarantee that the snapshot either succeeds, or fails with no changes.<ref>https://blog.devzero.be/post/kvm-live-vm-backup/</ref>
 
: <code>--quiesce</code> Libvirt will try to use guest agent to freeze and unfreeze domain’s mounted file systems. However, if domain has no guest agent, snapshot creation will fail. <ref>https://blog.devzero.be/post/kvm-live-vm-backup/</ref>
 
: <code>--quiesce</code> Libvirt will try to use guest agent to freeze and unfreeze domain’s mounted file systems. However, if domain has no guest agent, snapshot creation will fail. <ref>https://blog.devzero.be/post/kvm-live-vm-backup/</ref>
:: <code>error: argument unsupported: [[QEMU]] guest agent is not configured</code><ref>https://www.redhat.com/archives/libvirt-users/2015-December/msg00009.html</ref> (See: <code>[[virsh edit]]</code>)
+
:: <code>error: argument unsupported: [[QEMU guest agent]] is not configured</code><ref>https://www.redhat.com/archives/libvirt-users/2015-December/msg00009.html</ref> (See: <code>[[virsh edit]]</code>)
  
 
== Activities ==
 
== Activities ==

Revision as of 13:11, 4 February 2020

virsh snapshot-create-as domain[1] {[--print-xml] | [--no-metadata] [--halt] [--reuse-external]} [name] [description] [--disk-only [--quiesce]] [--atomic] [[--live] [--memspec memspec]] [--diskspec] diskspec]...


virsh snapshot-create-as [2]

--diskspec To indicate external snapshot and location
--disk-only Do not save memory information
--atomic
--no-metadata snapshot data is created, but any metadata is discarded (so libvirt does not treat the snapshot as current, and cannot revert to the snapshot unless virsh snapshot-create is used to teach libvirt about discarded metadata information). Useful if you plan to merge snapshots otherwise at a later point you have to explicitly clean the libvirt metadata (by invoking: virsh snapshot-delete vm1 --metadata [name|--current])[3] (See also: virsh snapshot-list)

Examples

virsh snapshot-create-as --domain MY_VM --name "Snapshot_2019_08" --description "Snapshot before critical operation" --live
  • Take a Disk state (--disk-only) (not memory) from a running VM (--live)
 virsh snapshot-create-as --domain MY_VM --name "Snapshot_disk_only_2019_08_MY_VM" --description "Disk snapshot only to disk" --disk-only --live --atomic 

[4]

  • Create a external snapshot --diskspec option, also using --no-metadata
virsh snapshot-create-as --domain MY_VM --name "napshot_disk_only_2019_08_MY_VM" --description "Disk snapshot only to disk" --disk-only --no-metadata --atomic --diskspec $TARGET,snapshot=external
Errors:
error: unsupported configuration: external snapshot file for disk hdXX already exists and is not a block device
Use virsh snapshot-list VMNAME to view snapshots

Other options

--no-metadata creates the snapshot, but any metadata is immediately discarded (that is, libvirt does not treat the snapshot as current, and cannot revert to the snapshot unless --redefine is later used to teach libvirt about the metadata again).
--atomic Libvirt will guarantee that the snapshot either succeeds, or fails with no changes.[5]
--quiesce Libvirt will try to use guest agent to freeze and unfreeze domain’s mounted file systems. However, if domain has no guest agent, snapshot creation will fail. [6]
error: argument unsupported: QEMU guest agent is not configured[7] (See: virsh edit)

Activities

  1. review --atomic operation option
  2. Virsh create live backups using virsh snapshot-create-as and virsh blockcommit
  • Related commands: virsh snapshot-info (Allows for example to verify if snapshot is internal or external)


Related commands

See also

  • http://manpages.ubuntu.com/manpages/eoan/man1/virsh.1.html#snapshot%20commands
  • http://manpages.ubuntu.com/manpages/eoan/man1/virsh.1.html#snapshot%20commands
  • https://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit
  • https://www.cyberciti.biz/faq/how-to-create-create-snapshot-in-linux-kvm-vmdomain/
  • https://blog.devzero.be/post/kvm-live-vm-backup/
  • https://blog.devzero.be/post/kvm-live-vm-backup/
  • https://www.redhat.com/archives/libvirt-users/2015-December/msg00009.html
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