Figured it out - it was the NFS client. I used snoop and then some dtrace magic to prove that the client (which was using O_SYNC) was sending very bursty requests to the system. I tried a number of other NFS clients with O_SYNC as well and got excellent performance when they were configured correctly. Just for fun I disabled the DDRdrive X1 (pair of them) that I use for the ZIL and performance tanked across the board when using O_SYNC. I can't recommend the DDRdrive X1 enough as a ZIL! Here is a great article on this behavior here: http://blogs.sun.com/brendan/entry/slog_screenshots
Thanks for the help all! -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss