Virsh snapshot-create-as

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

virsh snapshot-create-as

--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]) (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 

• 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.

--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.

error: argument unsupported: QEMU guest agent is not configured (See: virsh edit)

Activities

1. review --atomic operation option
2. Virsh create live backups using virsh snapshot-create-as and virsh blockcommit

See also

• virsh snapshot-info (Allows for example to verify if snapshot is internal or external)
• Virsh Snapshots: virsh snapshot-create-as, virsh snapshot-info, virsh snapshot-list, virsh blockjob, virsh snapshot-revert (Destructive action), virsh snapshot-delete
• virsh define
• qemu-img and qemu-img snapshot

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