On 3/6/2013 5:12 PM, Ric Wheeler wrote: > We actually test brutal "Power off" for xfs, ext4 and other file > systems. If your storage is configured properly and you have barriers > enabled, they all pass without corruption. Something that none of us mentioned WRT write barriers is that while the filesystem structure may avoid corruption when the power is cut, files may still be corrupted, in conditions such as any/all of these: 1. unwritten data still in buffer cache 2. drive caches are enabled 3. BBWC not working properly If the techs are determined to hard cut power because they don't have the time or the knowledge to do a clean shutdown, it may be well worth your time/effort to write a script and teach the field techs to execute it, before flipping the master switch. Your simple script would run as root, or you'd need to do some sudo foo within, and would contain something like: #! /bin/sh sync echo 2 > /proc/sys/vm/drop_caches echo "Ready for power down." This will flush pending writes in buffer cache to disk, and assumes of course that drive caches are disabled, and/or that BBWC, if present, is functioning properly. It also assumes no applications are still actively writing files, in which case you're screwed regardless. It's not a perfect solution and there's no guarantee you won't suffer file corruption, but this greatly increases your odds against it. -- Stan _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
