From owner-freebsd-questions@FreeBSD.ORG Sat Sep 2 13:40:31 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7966216A4DF for ; Sat, 2 Sep 2006 13:40:31 +0000 (UTC) (envelope-from kris@obsecurity.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.FreeBSD.org (Postfix) with ESMTP id 26E8B43D46 for ; Sat, 2 Sep 2006 13:40:31 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: from obsecurity.dyndns.org (elvis.mu.org [192.203.228.196]) by elvis.mu.org (Postfix) with ESMTP id D9D081A4D90; Sat, 2 Sep 2006 06:40:30 -0700 (PDT) Received: by obsecurity.dyndns.org (Postfix, from userid 1000) id 997BE51541; Sat, 2 Sep 2006 09:40:27 -0400 (EDT) Date: Sat, 2 Sep 2006 09:40:27 -0400 From: Kris Kennaway To: Skylar Thompson Message-ID: <20060902134026.GA65968@xor.obsecurity.org> References: <44F87733.2020405@squaretrade.com> <20060901213936.GA21561@xor.obsecurity.org> <44F8BCD9.4090308@cs.earlham.edu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="FCuugMFkClbJLl1L" Content-Disposition: inline In-Reply-To: <44F8BCD9.4090308@cs.earlham.edu> User-Agent: Mutt/1.4.2.2i Cc: Paul Lathrop , freebsd-questions@freebsd.org, Kris Kennaway Subject: Re: Snapshot performance X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Sep 2006 13:40:31 -0000 --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--