Date: Thu, 25 Jan 2018 17:58:04 -0800 From: Steve Kargl <sgk@troutmask.apl.washington.edu> To: Kirk McKusick <mckusick@mckusick.com> Cc: freebsd-fs@freebsd.org Subject: Re: Wedge system == lost files Message-ID: <20180126015804.GA51959@troutmask.apl.washington.edu> In-Reply-To: <201801260138.w0Q1cB7p046294@chez.mckusick.com> References: <20180125231409.GA940@troutmask.apl.washington.edu> <201801260138.w0Q1cB7p046294@chez.mckusick.com>
next in thread | previous in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20180126015804.GA51959>