On Sat, 10 Jan 2009, Dmitry Razguliaev wrote: > At the time of writing that post, no, I didn't run zpool iostat -v > 1. However, I run it after that. Results for operations of iostat > command has changed from 1 for every device in raidz to something in > between 20 and 400 for raidz volume and from 3 to something in > between 200 and 450 for a single device zfs volume, but the final > result remained the same: single disk zfs volume is only about twice > slower, then 9 disks raidz zfs volume, which seems to be very > strange. My expectations are in a range of 6-7 times difference in > performance.
Your expectations were wrong. Raidz and raidz2 will improve bulk sequential read/write with large files but they do nothing useful for random access or multi-user performance. There is also the issue that a single slow disk in a raidz or raidz2 vdev and drag down the performance of the whole vdev. Bob ====================================== Bob Friesenhahn bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
