[sheepdog] [PATCH v2 05/10] work: try to create worker threads in worker_thread_request_done

[Joseph Glanville]

Well I was thinking more in terms of cluster wide backup.

If you have the SHA1s of all read only objects then you can create
backup storage mechanisms that are content addressed.
Which means that you only need to ensure you have all unique objects
backed up along with the VDI tree/manifest.

You can also use it for dedup of stale/snapshot objects within the
cluster, when you discover duplicates you can repoint the links to
only keep the number of copies specified by the VDI with the largest
copy count.

Joseph.

On Mon, May 13, 2013 at 10:18 PM, Liu Yuan <namei.unix at gmail.com> wrote:
> On 05/14/2013 12:50 PM, Joseph Glanville wrote:
>> On a slightly related note are the hashes for readonly objects saved?
>> It would make sense to store them in the metadata for the objects so
>> they don't need to be recomputed after the first time.
>
> Looks good me to store sha1 as xattr for snapshot & stale objects at
> background, which will boots performance for recovery & 'vdi check' to a
> greater performance. But I am not sure if the benefit outweigh the added
> complexity.
>
> Thanks,
> Yuan