------------------ Original ------------------

From: "Eric Blake"<eblake@redhat.com>;

Date: Wed, Jun 6, 2012 08:24 PM

To: "SimpleCloud"<simplecloud@qq.com>;

Cc: "libvirt-users"<libvirt-users@redhat.com>;

Subject: Re: [libvirt-users] The default location of vm snapshots

On 06/06/2012 03:20 AM, SimpleCloud wrote:
> Hi all,
>
>
> Where could I find the memory dump and disk snapshots for vm after command "virsh snapshot-create <some_running_vm>"? Thanks in advance.

This particular form of snapshot is called the 'system checkpoint'
snapshot, and the current qemu implementation is that the snapshot
creates internal snapshots in your qcow2 files. If you do 'qemu-img
info $path_to_img', you will see the disk snapshots listed as internal
snapshots for each image associated with the domain, as well as the
first qcow2 file also having memory associated with the internal snapshot.

>
>
> I found the xml files in /var/lib/libvirt/qemu/snapshot/, but hava no idea about the raw snapshot file.

Looking in /var/lib/libvirt is generally unsupported (that is an
internal libvirt detail, and subject to change in future releases). The
only way to safely look at the snapshot XML is via the API
(virDomainSnapshotGetXMLDesc, which is wrapped by 'virsh snapshot-dumpxml').

I am also hoping to submit a patch that will allow you the option to
create an external snapshot rather than using qcow2 internal snapshots,
but that's not in the code base yet.

--
Eric Blake eblake@redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org