From owner-freebsd-fs@FreeBSD.ORG Thu Mar 23 18:43:08 2006 Return-Path: X-Original-To: freebsd-fs@freebsd.org Delivered-To: freebsd-fs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 177DE16A424; Thu, 23 Mar 2006 18:43:08 +0000 (UTC) (envelope-from john@kozubik.com) Received: from kozubik.com (kozubik.com [69.43.165.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id A8AD643D76; Thu, 23 Mar 2006 18:43:06 +0000 (GMT) (envelope-from john@kozubik.com) Received: from kozubik.com (localhost [127.0.0.1]) by kozubik.com (8.12.11/8.12.11) with ESMTP id k2NIh02w095019; Thu, 23 Mar 2006 10:43:00 -0800 (PST) (envelope-from john@kozubik.com) Received: from localhost (john@localhost) by kozubik.com (8.12.11/8.12.11/Submit) with ESMTP id k2NIgxn9095016; Thu, 23 Mar 2006 10:43:00 -0800 (PST) (envelope-from john@kozubik.com) Date: Thu, 23 Mar 2006 10:42:59 -0800 (PST) From: John Kozubik To: Kris Kennaway In-Reply-To: <20060323183414.GA84775@xor.obsecurity.org> Message-ID: <20060323103850.S55763@kozubik.com> References: <20060320224313.O55763@kozubik.com> <20060323183414.GA84775@xor.obsecurity.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: freebsd-fs@freebsd.org, jroberson@chesapeake.net, freebsd-current@freebsd.org, tegge@freebsd.org Subject: Re: UFS2 Snapshots in 6.1-Beta4 - Confirmed Problems X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Mar 2006 18:43:08 -0000 On Thu, 23 Mar 2006, Kris Kennaway wrote: > On Tue, Mar 21, 2006 at 01:36:44AM -0800, John Kozubik wrote: > > > First, I have confirmed that a filesystem with multiple snapshots that > > undergoes multiple, rapid deletions of files, will cause the system to > > hang. I have witnessed this before, but had not confirmed it or > > documented it in a PR. Now that I have confirmed this behavior, I have > > documented it in: kern/94769 > > I ran a (completion of) your script in a loop for about 24 hours and > it didn't deadlock. This may be because there was a second set of > fixes that was merged in to 6.x a day or two ago. Are you able to > confirm whether they indeed fixed this problem? What ratio of snapshots / rms did you run ? I reproduced this easily on 6.0-RELEASE and 6.1-BETA4. I am traveling right now and cannot test on anything newer. Can you try it on one of the two above, confirm for yourself that it manifests itself, and then compare that to what you see on whatever newer code you have ? If it is fixed, that's great. > > Second, kern/92292 is still a problem. I have reproduced this error in > > 6.1-BETA4 (and have seen it happening since 5.1). The (small) difference > > is that the cp process seems to stick in the flswai state instead of > > biowr. > > I'll test this one next. Great - thanks. It's less urgent, as running a md-backed FS on a snapshotted FS is less common, and easily avoided. The big fish are the rm problems (you can't avoid deleting things) and the "full filesystem" problems, since there is always a danger of that. ----- John Kozubik - john@kozubik.com - http://www.kozubik.com