On Tue, 26 Aug 2008, Darren J Moffat wrote: > Bob Friesenhahn wrote: >> On Tue, 26 Aug 2008, Darren J Moffat wrote: >>> >>> zfs set checksum=sha256 >> >> Expect performance to really suck after setting this. > > Do you have evidence of that ? What kind of workload and how did you test it
I did some random I/O throughput testing using iozone. While I saw similar I/O performance degredation to what you did (similar to your "large_db_oltp_8k_cached"), I did observe high CPU usage. The default fletcher algorithm uses hardly any CPU. In a dedicated file server, CPU usage is not a problem unless it slows subsequent requests. In a desktop system, or compute workstation, filesystem CPU usage competes with application CPU usage. With Solaris 10, enabling sha256 resulted in jerky mouse and desktop application behavior. Bob ====================================== Bob Friesenhahn [EMAIL PROTECTED], 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
