From owner-freebsd-stable@FreeBSD.ORG Fri Oct 31 15:48:28 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B3618106567C for ; Fri, 31 Oct 2008 15:48:28 +0000 (UTC) (envelope-from lopez.on.the.lists@yellowspace.net) Received: from mail.yellowspace.net (mail.yellowspace.net [80.190.200.164]) by mx1.freebsd.org (Postfix) with ESMTP id 461AA8FC08 for ; Fri, 31 Oct 2008 15:48:28 +0000 (UTC) (envelope-from lopez.on.the.lists@yellowspace.net) Received: from five.intranet ([62.216.211.194]) (AUTH: LOGIN lopez.on.the.lists@yellowspace.net) by mail.yellowspace.net with esmtp; Fri, 31 Oct 2008 16:48:26 +0100 id 0020018F.00000000490B28CA.000043E1 Message-Id: From: Lorenzo Perone To: Arnaud Houdelette In-Reply-To: <490B0F1D.2050606@tzim.net> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v929.2) Date: Fri, 31 Oct 2008 16:48:25 +0100 References: <200810220838.45900.fjwcash@gmail.com> <43E87CCF-6D36-4F82-BF54-7B705CB1EFB5@yellowspace.net> <1EA86BC6-349F-48DB-A77C-A4D8E00C55B5@cryptomonkeys.com> <490B0F1D.2050606@tzim.net> X-Mailer: Apple Mail (2.929.2) Cc: Louis Kowolowski , freebsd-stable@freebsd.org Subject: Re: ZFS X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Oct 2008 15:48:28 -0000 > I use ZFS since 7.0-RELEASE. I'm currently using latest stable. > Ok the load is not as a production one, as the box is used as a home > server (NAS), but the hardware is limited too (only 512MB of RAM, > mono-core A64 3200+, motherborad integrated sata controler). > I tried to stress the filesystem a bit with multiple simultaneous > rsyncs. No glitches. The only failures was when swap was on a zvol > instead of the system drive. Even with more ram, it regularely ended > in panics or deadlocks (most of the time, deadlocks) under "high" > load. > > Not sure of anything here, but you might want to try with non-zfs > swap - on another drive(s) or dedicated slices ? Yep, I think I'm going to use a separate slice for the pool, mounting into the respective jails only the needed filesystems: mypool/mail into /jails/mail/maildataroot mypool/db into /jails/web/mysql-bup-slave (or sort of) and then use frequent snapshots for mypool/mail (even hourly or so), and for the database, a few times per day mysql-backup-slave.sh stop, zfs snapshot mypool/db, mysql-backup-slave.sh start.. the mysql slave snapshotting is really a goodness which I've used on a SunOS with zfs and really rocks. So I never shutdown the master, the slave goes down only a few seconds, and the database filesystem is consistent and synced. In the current case, I think it is not only a feature but also a must: _If_ the host deadlocks and mysql fails to sync, at least I have a working snapshot of the data. I wouldn't put the master itself on zfs for now, but if all goes well for a while, why not. BTW: while sync does not work anymore in a deadlock situation, I've seen that fsync mostly still does. So something like find /var/db/mysql -type f -exec fsync {} \; can save your files if the db is running on UFS.. Thanx & Regards! Lorenzo