From owner-freebsd-questions@FreeBSD.ORG Thu Oct 6 01:51:43 2011 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5E984106564A for ; Thu, 6 Oct 2011 01:51:43 +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 2A4108FC12 for ; Thu, 6 Oct 2011 01:51:42 +0000 (UTC) Received: from [192.168.1.50] (Mac-Pro.magehandbook.com [192.168.1.50]) by mail.magehandbook.com (Postfix) with ESMTP id 39295835; Wed, 5 Oct 2011 21:51:42 -0400 (EDT) Date: Wed, 05 Oct 2011 21:51:42 -0400 From: Daniel Staal To: Dave Cundiff Message-ID: <15370081D51E465D77FAAA41@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-fs@freebsd.org, questions@freebsd.org Subject: Re: ZFS Write Lockup X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: FreeBSD Questions List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Oct 2011 01:51:43 -0000 --As of October 5, 2011 6:37:17 PM -0400, Dave Cundiff is alleged to have said: > Its for a backup service I've been working on. It takes a snapshot > hourly of all 17 zvols. I was planning on keeping them for a month. > > I had the same thought about the snapshots and deleted them all > yesterday. It appears there is some issue with keeping that many. I > removed them all and the zvols are now functioning correctly. Its > strange that the large number didn't cause incremental slowdown. While > the snapshots were still there the IO was normal when it wasn't acting > up. Just it would have spurts of almost total lockup until I performed > a snapshot removal operation or 2. --As for the rest, it is mine. Look at sysutils/zfs-periodic. It does that type of backup, although it doesn't keep quite as many. (Several hourly, daily, weekly, and monthly. Configurable. I have 38 filesystems, and 780 snapshots. (Only one volume, though.)) And that definitely sounds like a bug. Gradual slowdowns would be expected if you were just reaching performance limits, but sudden stops sound like there's a condition that doesn't work someplace, or some loop the system can get into. 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. ---------------------------------------------------------------