[libvirt-users] Update on-disk XML after virsh snapshot-create-as

Andrew Martin amartin at xes-inc.com
Tue Apr 14 15:17:42 UTC 2015


Hello,

I am using "virsh snapshot-create-as" to create external snapshots of running
VMs using libvirt 1.0.2 on Ubuntu 12.04 and libvirt 1.2.2 on Ubuntu 14.04. This
works well for creating the snapshots, but I notice that the on-disk XML file
in /etc/libvirt/qemu is not updated with the new disk image file after the
snapshot is created. This appears to be very similar to
https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1403841, but occurs on
both 12.04 and 14.04 so I am not sure it is the same bug.

This presents a problem if the virtual machine host is suddenly powered off
since a subsequent boot will find the VM using an older image file to boot
rather than the most recent snapshot. Is it safe for me to use an external
wrapper script that does the following to ensure the on-disk XML is up-to-date:
virsh snapshot-create-as ....  
virsh dumpxml > /etc/libvirt/qemu/<domain>.xml

Is it safe for me to overwrite the contents of /etc/libvirt/qemu/<domain>.xml
manually while the VM is running?

Thanks,

Andrew Martin




More information about the libvirt-users mailing list