From owner-freebsd-questions@FreeBSD.ORG Fri Jun 1 00:34:17 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7C80A106566B for ; Fri, 1 Jun 2012 00:34:17 +0000 (UTC) (envelope-from freebsd@pki2.com) Received: from btw.pki2.com (btw.pki2.com [IPv6:2001:470:a:6fd::2]) by mx1.freebsd.org (Postfix) with ESMTP id 241D48FC19 for ; Fri, 1 Jun 2012 00:34:17 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by btw.pki2.com (8.14.5/8.14.5) with ESMTP id q510YCut080523; Thu, 31 May 2012 17:34:12 -0700 (PDT) (envelope-from freebsd@pki2.com) From: Dennis Glatting To: Daniel Staal In-Reply-To: <70D99F583BF63C05BB39CCAF@mac-pro.magehandbook.com> References: <70D99F583BF63C05BB39CCAF@mac-pro.magehandbook.com> Content-Type: text/plain; charset="ISO-8859-1" Date: Thu, 31 May 2012 17:34:12 -0700 Message-ID: <1338510852.77553.1.camel@btw.pki2.com> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit X-yoursite-MailScanner-Information: Dennis Glatting X-yoursite-MailScanner-ID: q510YCut080523 X-yoursite-MailScanner: Found to be clean X-MailScanner-From: freebsd@pki2.com Cc: freebsd-questions@freebsd.org Subject: Re: Anyone using freebsd ZFS for large storage servers? 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: Fri, 01 Jun 2012 00:34:17 -0000 On Thu, 2012-05-31 at 19:27 -0400, Daniel Staal wrote: > --As of May 31, 2012 11:24:41 AM -0700, Dennis Glatting is alleged to have > said: > > > 2) Under heavy I/O my systems freeze for a few seconds. I haven't looked > > into why but they are completely unresponsive. Note I am also using > > compressed volumes (gzip), which puts a substantual load on the kernel. > > --As for the rest, it is mine. > > I'm not using as huge a dataset, but I was seeing this behavior as well > when I first set my box up. What was happening was that ZFS was caching > *lots* of writes, and then would dump them all to disk at once, during > which time the computer was completely occupied with the disk I/O. > > The solution (suggested from ) for > me was: > vfs.zfs.txg.timeout="5" > Was already set: mc# sysctl vfs.zfs.txg.timeout vfs.zfs.txg.timeout: 5 > in loader.conf. That only allows it to cache writes for 5 seconds, instead > of the default 30. This appears to be the default in the latest versions > of FreeBSD, so if you are running an upgraded 9, ignore me. ;) (But check > the page linked above: There are other suggestions to try.) > > Daniel T. Staal > > --------------------------------------------------------------- > This email copyright the author. Unless otherwise noted, you > are expressly allowed to retransmit, quote, or otherwise use > the contents for non-commercial purposes. This copyright will > expire 5 years after the author's death, or in 30 years, > whichever is longer, unless such a period is in excess of > local copyright law. > ---------------------------------------------------------------