In response to Olivier Mueller <om-lists-...@omx.ch>: > Hello, > > $ df -m ; date ; rm -r templates_c ; df -m ; date > Filesystem 1M-blocks Used Avail Capacity Mounted on > /dev/da0s1a 989 45 864 5% / > /dev/da0s1f 128631 102179 16160 86% /usr > [...] > Wed May 6 00:23:01 CEST 2009 > > Filesystem 1M-blocks Used Avail Capacity Mounted on > /dev/da0s1a 989 45 864 5% / > /dev/da0s1f 128631 69844 48496 59% /usr > Wed May 6 12:21:02 CEST 2009 > > > -> it took about 12 hours to delete these 30GB of files and > sub-directories (smarty cache files: many small files in many dirs). > It's a little bit surprising, as it's on a recent HP proliant DL360 g5 > with SAS disks (Raid1) running freebsd 6.x > ( /dev/da0s1f on /usr (ufs, local, soft-updates) ) > > Surprisingly, cpu load remained quite low during the operation (apache > stayed responsive). Is it a known problem on this kind of hardware or > something related to the filesystem? Is there a way to improve this? > Even on my $500 PC with IDE disks this goes quicker... :) > > I checked > http://www.freebsd.org/doc/en/books/handbook/configtuning-disk.html but > I'm not sure if this would help in this case. Any suggestion how I can > "fix" that?
With lots of small files, the time involved is far less dependent on the size of data, and much more dependent on the number of files, and the resultant number of directory entries that need to be updated. "Lots" isn't a particularly accurate count of the # of files, but if you're talking web cache files, I'll guess they average 5k each, which means you had 6 million files. df -i would have been more useful in the output above. This brings a number of questions up: * Are you _sure_ softupdates is enabled on that partition? That's going to make the biggest improvement in speed. * Are these 7200RPM disks or 15,000? Again, going to make a big difference. * If apache was still running, is it possible that it was creating enough disk activity to slow the activity down? Running top -m io will show you how much disk IO each process is creating. * When you compared the speed to your laptop, did you delete 6 million files from the laptop? If you deleted a single 30G file, then you're comparing apples to atom bombs. If this is a directory that you blow away on a regular schedule, you'd do much better to make it a dedicated partition and simply reformat it. -- Bill Moran http://www.potentialtech.com http://people.collaborativefusion.com/~wmoran/ _______________________________________________ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "freebsd-performance-unsubscr...@freebsd.org"
