On Sat, Oct 12, 2013 at 1:47 AM, Fam Zheng <f...@redhat.com> wrote: > While mirroring write is a good idea, doing it with drive-backup is probably > not. The function of this command is to 'backup' the image with existing data, > instead of new data. With your 'stream' mode, this semantic is changed.
I'm not so sure. I think that it would be better to switch between semantics with 'modes' rather than 'commands' to reduce documentation, duplicate code, and burden on users to remember different commands. Thus, many of the _modes_ of 'drive-backup' might provide you with point-in-time snapshots of a block device, but some of them might just mirror writes for backup purposes other than a point-in-time snapshot. > IMO this feature is best implemented as a block filter, which is currently > being discussed and not ready yet. A second option may be doing with another > command (e.g. block-mirror, or a new one?) That may be true, as I haven't followed block filters very closely yet, but it seemed simple enough with the nice drive-backup code to easily implement. Perhaps this 'mode' could be refactored in the future to use block filters. -- Wolf
