On Fri, 18 Feb 2011, Jeremy Chadwick wrote: JC> > KDM> The best stress test I have found has been to just do a single sequential JC> > KDM> write stream with ZFS. i.e.: JC> > KDM> JC> > KDM> cd /path/to/zfs/pool JC> > KDM> dd if=/dev/zero of=foo bs=1M JC> > KDM> JC> > KDM> Just let it run for a long period of time and see what happens. JC> > JC> > Well, provided that I'm plannign to use ZFSv28 to be in place, wouldn't be JC> > /dev/random more appropriate? JC> JC> No -- /dev/urandom maybe, but not /dev/random. /dev/urandom will also JC> induce significantly higher CPU load than /dev/zero will. Don't forget JC> that ZFS is a processor-centric (read: no offloading) system.
We're not on Linux: root@beaver:/FreeBSD/src.8# l /dev/*random crw-rw-rw- 1 root wheel 0, 23 Feb 15 13:50 /dev/random lrwxr-xr-x 1 root wheel 6 Feb 15 13:50 /dev/urandom@ -> random JC> I tend to try different block sizes (starting at bs=8k and working up to JC> bs=256k) for sequential benchmarks. The "sweet spot" on most disks I've JC> found is 64k. Otherwise use benchmarks/bonnie++. Ah yes, bonnie++ was on my list too, thanks for the reminder. -- Sincerely, D.Marck [DM5020, MCK-RIPE, DM3-RIPN] [ FreeBSD committer: [email protected] ] ------------------------------------------------------------------------ *** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- [email protected] *** ------------------------------------------------------------------------ _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
