Re: [libvirt] A couple of questions on snapshot-create/ snapshot-create-as

On 04/30/2012 06:17 AM, Kashyap Chamarthy wrote: Not yet, but it's on my list of things to add. For now, this is true. http://libvirt.org/html/libvirt-libvirt.html#virDomainSnapshotCreateXML (Yuck - our online doc conversion loses paragraph breaks, and isn't understanding how to mark up parameter names). --quiesce maps to VIR_DOMAIN_SNAPSHOT_CREATE_QUIESCE, which requests that if the guest has a guest agent running, then connect to that agent and request that the file systems be frozen before taking the snapshot (that way, you can then directly boot the snapshot without having to run fsck). --atomic maps to VIR_DOMAIN_SNAPSHOT_CREATE_ATOMIC. If you are using qemu 1.0 or earlier, this flag will fail unless you only snapshot a single disk; if you are using qemu 1.1 or later, this flag will ensure that the qemu monitor command 'transaction' is used to ensure an atomic snapshot. Omitting the flag has no change of behavior on qemu 1.1, but on qemu 1.0 or earlier, the snapshot is attempted, but if you fail partway through, then you may be left with a domain where half the disks had a snapshot and the other half did not. --reuse-external maps to VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT, which states that rather than having libvirt create the snapshot file from scratch, you will pre-create the file. This is useful for applications like VDSM that want the snapshot to be pre-created with a relative backing file name in the qcow2 metadata (libvirt would create it with an absolute backing file name). -- Eric Blake eblake(a)redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org