On Sun, Jan 10, 2010 at 7:16 PM, Chris Webb <[email protected]> wrote: > MORITA Kazutaka <[email protected]> writes: > >> - create a clone image (only from a sheepdog image) > > Hi. Can I clarify the semantics of this operation? Am I right that > > - you can clone a new image from a snapshot of an existing image, but not > directly from an existing image;
Yes. It is same as zvol of ZFS and Amazon EBS. > - one you've cloned a new image, you will be able to delete the source > snapshot and the whole original image without losing the clone, going > from two references counts to the shared blocks to just one again? Yes, sheepdog is expected to be so. > With my "infrastructure provider's" hat on, the other piece of information > which exists inside sheepdog and would be nice to expose is a way to know > which blocks differ between two snapshots of the same image. This could then > be used to efficiently implement offsite backup to another sheepdog cluster, > just sending the block-diffs from the previous backup. Perhaps another > operation to include in the client library? Thanks for the valuable advice! Such a operation is not supported yet. Implementing the following operations looks to be useful, yes? - make a patch $ shepherd diff src_vdi:src_tag dst_vdi:dst_tag > delta_file - apply a patch $ shepherd apply vdi:tag delta_file Regards, Kazutaka Morita -- sheepdog mailing list [email protected] http://lists.wpkg.org/mailman/listinfo/sheepdog
