From owner-freebsd-current@FreeBSD.ORG Wed Dec 23 20:37:52 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0E6E0106566B for ; Wed, 23 Dec 2009 20:37:52 +0000 (UTC) (envelope-from dpd@bitgravity.com) Received: from mail1.sjc1.bitgravity.com (mail1.sjc1.bitgravity.com [209.131.97.19]) by mx1.freebsd.org (Postfix) with ESMTP id ED5828FC08 for ; Wed, 23 Dec 2009 20:37:51 +0000 (UTC) Received: from [209.131.110.169] (helo=netops-169.sfo1.bitgravity.com) by mail1.sjc1.bitgravity.com with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1NNXh1-000280-Fb; Wed, 23 Dec 2009 12:20:23 -0800 Mime-Version: 1.0 (Apple Message framework v1077) Content-Type: text/plain; charset=us-ascii From: "David P. Discher" In-Reply-To: Date: Wed, 23 Dec 2009 12:20:23 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: References: <39309F560B98453EBB9AEA0F29D9D80E@vosz.local> <3bbf2fe10912181004w2a1abff2re8f77fd6a8bc3233@mail.gmail.com> To: Alexander Zagrebin X-Mailer: Apple Mail (2.1077) Cc: 'Attilio Rao' , freebsd-current@freebsd.org Subject: Re: 8.0-RELEASE: disk IO temporarily hangs up (ZFS or ATA related problem) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Dec 2009 20:37:52 -0000 ZFS will write buffer ALOT. Your settings of vfs.zfs.arc_min and = vfs.zfs.arc_max will likely affect how bursty this is. I've been = running with Min, 32 GB arc, and see very bursty writes (of course, my = systems have 64GB).=20 Also, use 'zpool iostat 1' and not the system iostat. Check gstat as = well. also try using CAM_ATA (ahci.ko) instead of ad devices, so your can get = the benefits of tag queuing. There is also a possible undocumented issue with, I believe it was the = WD green drives, where the vibration of the drive actually slowed it = down. This was demonstrated by setting a pound or two of silly putty on = the top of the drive, and its performance (significantly) increased. = Experiment with putting some heavily, non-conductive weight on top of = each drive - a book or something. ensure that is its securely mounted = as well.=20 --- David P. Discher dpd@bitgravity.com * AIM: bgDavidDPD BITGRAVITY * http://www.bitgravity.com On Dec 18, 2009, at 12:04 PM, Alexander Zagrebin wrote: >>> The disks are used for mirrored ZFS pool. >>> I have noticed that the system periodically locks up on=20 >> disk operations. >>> After approx. 10 min of very slow disk i/o (several KB/s)=20 >> the speed of disk >>> operations restores to normal. >>> gstat has shown that the problem is in ad6. >>=20 >> Want you try this patch and report?: >> http://people.freebsd.org/~attilio/lockmgr_lostwake.diff >>=20 >> It should apply to STABLE_8 and if not, just report and I will help. >=20 > Thanks fo your attempt to help! > I've successfully applied this patch to RELENG_8_0, recompiled > kernel and required modules (krpc, opensolaris,zfs), > but nothing has changed. The problem still exist. >=20 > --=20 > Alexander Zagrebin >=20 > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to = "freebsd-current-unsubscribe@freebsd.org"