Image Backup

Some people might want to read images out of Sheepdog cluster and store them as local images which can be copied to somewhere else, we can actually convert it by:

$ qemu-img sheepdog:image -O qcow2 backup_name

Then you can see a qcow2(you can specify other formats) image named backup_name on your local disk.

Besides 'qemu-img convert', we can also use 'vdi read/write/setattr/getattr' the sheepdog images. And we can even export Sheepdog images as a pseudo block file in the local file system hierarchy via Sheepfs and use common tools like scp to directly transport to wherever you want as a raw image (This will save one extra conversion to local file).

Sheepdog supports yet another backup mechanism: backup differential data between two snapshots. See more info at incremental snapshot backup