On 05/23/2014 12:16 PM, Andrew Martin wrote:
--quiesce requires the guest to be running to work, while --memspec forceably stops the guest (the migration algorithm must pause, even if --live minimizes the pause to a fraction of a second). Would calling snapshot-create-as with --disk-only and --quiese still succeed on a VM that is stopped (since the disk would already be consistent, it would just call "qemu-img create")?
For an offline guest, --disk-only makes no difference (there is no memory to worry about); and you are correct that the disk is consistent (assuming the OS has a clean shutdown before going offline). Yes, calling 'qemu-img create' is basically what libvirt does for an offline external snapshot. However, a paused/stopped guest cannot respond to a quiesce request (the guest agent only works if the guest is running), so your attempt to use --quiesce would fail; you'd have to omit the parameter if the guest is stopped. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org