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<p>Normally when I backup a kvm machine I shutdown the machine then run:</p>
<pre><code>virsh list -all
virsh shutdown Ubuntu18
virsh dumpxml Ubuntu18 > /MyBackup/Ubuntu18.xml
cp /var/lib/libvirt/images/Ubuntu18.qcow2 /MyBackup/Ubuntu18.qcow2
</code></pre>
<p>However, I found a new sub-command. The help file says:</p>
<pre><code>% virsh backup-begin --help
NAME
backup-begin - Start a disk backup of a live domain
SYNOPSIS
backup-begin <domain> [--backupxml <string>] [--checkpointxml <string>] [--reuse-external]
DESCRIPTION
Use XML to start a full or incremental disk backup of a live domain, optionally creating a checkpoint
OPTIONS
[--domain] <string> domain name, id or uuid
--backupxml <string> domain backup XML
--checkpointxml <string> domain checkpoint XML
--reuse-external reuse files provided by caller
</code></pre>
<p>The problem with this help is, it is not clear enough.</p>
<p>I understand that I should use <code>virsh backup-begin vm1</code> to backup a live kvm machine. However, this command only create <code>.qcow2</code> files. What about the <code>.xml</code> file.</p>
<p>What does <code>--backupxml</code> , <code>--checkpointxml</code> & <code>--reuse-external</code> actually do? </p><p>When should I use them?</p></div></div>