[sheepdog-users] About snapshots

[Liu Yuan]

On Fri, Aug 16, 2013 at 10:48:17AM +0200, Ing. Luca Lazzeroni - Trend Servizi Srl wrote:
> Hi,
> I'm trying to use external snapshot feature of QEMU/libVirt with sheepdog baked vdi to take VDI live backups without using sheepdog snapshots.
> This is to avoid the problem of disk-space unreleased on snapshot deletion.

Maybe you can simply use qemu-img sheepdog:image local_iamge to read the image
out of cluster?

The release of unused objects from deleted snapshots will be supported in the
up comming series of v0.7.x, I guess in about one month or two.

> The main problem is that virsh seems to fail to create external snapshot (baked on qcow2 files on local server filesystem) on vm running within sheepdog, probably due to qemu inability to create disk-mirror across the 2 storage technologies (sheepdog / local fs).
> 
> Is anyone trying to do this ? Or is this the wrong way to take full backups ?

I think 'dog cluster snapshot' will serve you better for 'full backups'

See https://github.com/sheepdog/sheepdog/wiki/Backend-Stores%2C-Object-Cache-and-Disk-Cache#cluster-backup

Thanks
Yuan