Re: What does the positional parameters of "virsh backup-begin" actually do?

is under the control of whatever third party connects to the NBD export)

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?