From owner-freebsd-questions@FreeBSD.ORG Thu May 31 23:33:46 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 DEDD1106564A for ; Thu, 31 May 2012 23:33:46 +0000 (UTC) (envelope-from DStaal@usa.net) Received: from mail.magehandbook.com (173-8-4-45-WashingtonDC.hfc.comcastbusiness.net [173.8.4.45]) by mx1.freebsd.org (Postfix) with ESMTP id B07E98FC18 for ; Thu, 31 May 2012 23:33:46 +0000 (UTC) Received: from [192.168.1.50] (Mac-Pro.magehandbook.com [192.168.1.50]) by mail.magehandbook.com (Postfix) with ESMTP id 3W3Pww2NvGz1Mf; Thu, 31 May 2012 19:28:00 -0400 (EDT) Date: Thu, 31 May 2012 19:27:19 -0400 From: Daniel Staal To: Dennis Glatting Message-ID: <70D99F583BF63C05BB39CCAF@mac-pro.magehandbook.com> In-Reply-To: References: X-Mailer: Mulberry/4.0.8 (Mac OS X) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline 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: Thu, 31 May 2012 23:33:46 -0000 --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" 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. ---------------------------------------------------------------