Am 05.01.2010 16:22, schrieb Mikko Lammi:
However when we deleted some other files from the volume and managed to raise free disk space from 4 GB to 10 GB, the "rm -rf directory" method started to perform significantly faster. Now it's deleting around 4,000 files/minute (240,000/h - quite an improvement from 10,000/h). I remember that I saw some discussion related to ZFS performance when filesystem becomes very full, so I wonder if that was the case here.
I did some tests. They were done on an Ultra 20 (2.2 GHz Dual-Core Opteron) with crappy SATA disks. On this machine creation and deletion of files were I/O bound. I was able to create about 1 Mio. files per hour. I stopped after 5 hours, so I had approx. 5 Mio. files in one directory.
Deletion (via the Perl script) also had a rate of ~1 Mio. files per hour. During deletion the disks (mirrored zpool) were both 95% busy, CPU time was 5% total.
If the T1000 has SCSI disks you can turn on write cache on both disks (though in my tests on delete most I/O were read operations). For the rpool it will probably not be enabled by default because your are "just" using partitions:
# format -e [select disk] format> scsi scsi> p8 b2 |= 4 Mode select on page 8 ok. scsi> quit Disable write cache: scsi> p8 b2 &= ~4 (Yes I know, there is a "cache" command in format, but I'm used to above commands a long time before the "cache" command was introduced) Daniel _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
