On Fri, Jan 14, 2022 at 23:39:10 +0600, Ahmad Ismail wrote:
> Normally when I backup a kvm machine I shutdown the machine then run:
[...]
> The problem with this help is, it is not clear enough.
>
> I understand that I should use virsh backup-begin vm1 to backup a live kvm
> machine. However, this command only create .qcow2 files. What about the .xml
> file.
>
> What does --backupxml , --checkpointxml & --reuse-external actually do?
>
> When should I use them?
'man virsh' states:
backup-begin
Syntax:
backup-begin domain [backupxml] [checkpointxml] [--reuse-external]
Begin a new backup job. If backupxml is omitted, this defaults to
a full backup using a push model to filenames generated by lib‐
virt; supplying XML allows fine-tuning such as requesting an in‐
cremental backup relative to an earlier checkpoint, controlling
which disks participate or which filenames are involved, or re‐
questing the use of a pull model backup. The backup-dumpxml com‐
mand shows any resulting values assigned by libvirt. For more in‐
formation on backup XML, see:
https://libvirt.org/formatbackup.html
If --reuse-external is used it instructs libvirt to reuse tempo‐
rary and output files provided by the user in backupxml.
If checkpointxml is specified, a second file with a top-level ele‐
ment of domaincheckpoint is used to create a simultaneous check‐
point, for doing a later incremental backup relative to the time
the backup was created. See checkpoint-create for more details on
checkpoints.
This command returns as soon as possible, and the backup job runs
in the background; the progress of a push model backup can be
checked with domjobinfo or by waiting for an event with event (the
progress of a pull model backup is under the control of whatever
third party connects to the NBD export). The job is ended with
domjobabort.
Does this clarify it sufficiently?
