Messages in this thread | | | Date | Thu, 9 Jun 2011 06:52:20 -0400 | From | Christoph Hellwig <> | Subject | Re: LVM vs. Ext4 snapshots (was: [PATCH v1 00/30] Ext4 snapshots) |
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On Wed, Jun 08, 2011 at 09:26:11PM +0300, Amir G. wrote: > In my old next3.sf.net wiki, which I do update from time to time, > I listed 4 advantages of Ext4 (then next3) snapshots over LVM: > * Performance: only small overhead to write performance with snapshots > * Scalability: no extra overhead per snapshot > * Maintenance: no need to pre-allocate disk space for snapshots > * Persistence: snapshots don't vanish when disk is full > > As far as I know, the only thing that has changed from dm-snap > to dm-multisnap is the Scalability.
I don't think you have looked at dm-multisnap at all, have you? It addresses all your points and many more. Take a look at the code which is in the multisnap branch of https://github.com/jthornber/linux-2.6/, there's also some slides on it from Linuxtag at:
https://github.com/jthornber/storage-papers/blob/master/thinp-snapshots-2011/thinp-and-multisnap.otp?raw=true
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