From owner-freebsd-fs@freebsd.org Fri Jan 26 01:58:06 2018 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 89F2AEDC0AD for ; Fri, 26 Jan 2018 01:58:06 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.76.21]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "troutmask", Issuer "troutmask" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 1426C7D104 for ; Fri, 26 Jan 2018 01:58:06 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (localhost [127.0.0.1]) by troutmask.apl.washington.edu (8.15.2/8.15.2) with ESMTPS id w0Q1w4va054783 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 25 Jan 2018 17:58:04 -0800 (PST) (envelope-from sgk@troutmask.apl.washington.edu) Received: (from sgk@localhost) by troutmask.apl.washington.edu (8.15.2/8.15.2/Submit) id w0Q1w4s7054779; Thu, 25 Jan 2018 17:58:04 -0800 (PST) (envelope-from sgk) Date: Thu, 25 Jan 2018 17:58:04 -0800 From: Steve Kargl To: Kirk McKusick Cc: freebsd-fs@freebsd.org Subject: Re: Wedge system == lost files Message-ID: <20180126015804.GA51959@troutmask.apl.washington.edu> Reply-To: sgk@troutmask.apl.washington.edu References: <20180125231409.GA940@troutmask.apl.washington.edu> <201801260138.w0Q1cB7p046294@chez.mckusick.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201801260138.w0Q1cB7p046294@chez.mckusick.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Jan 2018 01:58:06 -0000 On Thu, Jan 25, 2018 at 05:38:11PM -0800, Kirk McKusick wrote: > > To: freebsd-current@freebsd.org > > Subject: Wedge system == lost files > > > > So, my system just wedge itself. No panic. No keyboard. > > No mouse. No remote login. Nothing. Just wedged. > > > > The system is FreeBSD 12.0-CURRENT r326432 Fri Dec 1 2017 amd64. > > > > Imagine my surprise when I rebooted system and the file > > I had been editing (and saving after every change) is > > gone. /usr/lost+found is empty. The file pl19-21.tex is > > gone along with a few files from latex. > > > > -rw-r--r-- 1 kargl kargl - 0 Jan 25 14:53 pl19-21.aux > > -rw-r--r-- 1 kargl kargl - 0 Jan 25 14:53 pl19-21.log > > -rw-r--r-- 1 kargl kargl - 0 Jan 25 14:53 pl19-21.out > > -rw-r--r-- 1 kargl kargl - 0 Jan 25 14:53 pl19-21.pdf > > -rw-r--r-- 1 kargl kargl - 0 Jan 25 14:52 pl19-21.tex > > > > /dev/ada0p5 on /usr (ufs, local, journaled soft-updates) > > > > Are there known issues with SUJ, again? > > > > I have not seen any recent issues with SUJ other than a complaint > that it corrupted cylinder-group check hashes (which has been fixed). > > A hanging system as you describe can occur if your system disk > locks up, though the machine generally does remain pingable. But > it would explain missing files if the system had not been able to > flush them out (the writes simply accumulate in memory). But most > editors do an fsync after each file is written which would have > hung if you could not write to the disk. > > So, regretably, I do not have an explanation. If you are suspicious > about SUJ, you can disable it using: > > tunefs -j disable /dev/ada0p5 > > That will leave soft updates enabled so will not cause a slowdown > in your disk throughput. > Thanks for the quick reply. I suppose I'm surprise that pl19-21.tex is completely gone. It was sitting on disk for awhile before I started editing it. Your explanation of the buffer cache not getting written to disk probably explains why the other files are gone. I'll chalk it up as a burp with my system. -- Steve