On Fri, Sep 01, 2006 at 04:06:01PM -0700, Skylar Thompson wrote: > Kris Kennaway wrote: > > On Fri, Sep 01, 2006 at 11:08:51AM -0700, Paul Lathrop wrote: > > > >> Hi all, > >> > >> We're working on deploying a new mail server on FreeBSD 6.1-STABLE. One > >> of the major selling points was the ability to take filesystem snapshots > >> in order to make backups from a consistent filesystem on such a > >> high-traffic system. Unfortunately, when I take a snapshot, performance > >> slows to a crawl - to the point where the system stops responding to > >> network requests (ping, SMTP, etc.). Also, the snapshot takes 10-15 > >> minutes to complete. > >> > >> Is this a typical situation? Will I need to schedule downtime for > >> backups in spite of this nifty new feature? Am I doing something wrong? > >> > > > > Time depends on the size of the filesystem - but you are correct that > > snapshots were not designed with performance in mind (rather, to speed > > up booting after an unclean shutdown by removing the need to wait for > > fsck). > > > > Kris > > > Are there plans to improve performance of snapshots? Using the > freebsd-snapshot port to link FS snapshots to the automounter is pretty > nifty, but it does kill I/O performance while that's in progress as the > OP mentioned.
Unfortunately I don't think anyone is working on it. The closest thing on the horizon is ZFS support which does feature high-performance snapshots. This is still a way off though. Kris
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