Date: Sat, 2 Sep 2006 09:40:27 -0400 From: Kris Kennaway <kris@obsecurity.org> To: Skylar Thompson <skylar@cs.earlham.edu> Cc: Paul Lathrop <plathrop@squaretrade.com>, freebsd-questions@freebsd.org, Kris Kennaway <kris@obsecurity.org> Subject: Re: Snapshot performance Message-ID: <20060902134026.GA65968@xor.obsecurity.org> In-Reply-To: <44F8BCD9.4090308@cs.earlham.edu> References: <44F87733.2020405@squaretrade.com> <20060901213936.GA21561@xor.obsecurity.org> <44F8BCD9.4090308@cs.earlham.edu>
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--FCuugMFkClbJLl1L Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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: > > =20 > >> 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 snapsho= ts > >> 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? > >> =20 > > > > 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 > > =20 > 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 --FCuugMFkClbJLl1L Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (FreeBSD) iD8DBQFE+YnKWry0BWjoQKURAig9AKD1Fzx5r7EekqEd/Yalal+nsmg19ACbBFZn 7f0js4/hFRSTR0K2v2A4fFg= =UmQP -----END PGP SIGNATURE----- --FCuugMFkClbJLl1L--
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