Pool is 6x striped Stec ZEUSRam as ZIL, 6x OCZ Talos C 230GB drives L2ARC, and 24x 15k SAS drives striped (no parity, no mirroring) - I know, terrible for reliability, but I just want to see what kind of IO I can hit. Checksum is ON - can't recall what default is right now. Compression is off Dedupe is off
Trying to figure out vdbench right now, but apparently that's beyond my abilities at 8:30PM :( -----Original Message----- From: Bob Friesenhahn [mailto:bfrie...@simple.dallas.tx.us] Sent: Tuesday, July 24, 2012 8:13 PM To: matth...@flash.shanje.com Cc: zfs-discuss@opensolaris.org Subject: Re: [zfs-discuss] IO load questions On Tue, 24 Jul 2012, matth...@flash.shanje.com wrote: > > ~50,000 IOPS 4k random read. 200MB/sec, 30% CPU utilization on > Nexenta, ~90% utilization on guest OS. I?m guessing guest OS is > bottlenecking. Going to try physical hardware next week > ~25,000 IOPS 4k random write. 100MB/sec, ~70% CPU utilization on > Nexenta, ~45% CPU utilization on guest OS. Feels like Nexenta CPU is > bottleneck. Load average of 2.5 > > A quick test with 128k recordsizes and 128k IO looked to be 400MB/sec > performance, can?t remember CPU utilization on either side. Will > retest and report those numbers. > > It feels like something is adding more overhead here than I would > expect on the 4k recordsizes/IO workloads. Any thoughts where I should start on this? > I?d really like to see closer to 10Gbit performance here, but it seems > like the hardware isn?t able to cope with it? All systems have a bottleneck. You are highly unlikely to get close to 10Gbit performance with 4k random synchronous write. 25K IOPS seems pretty good to me. The 2.4GHz clock rate of the 4-core Xeon CPU you are using is not terribly high. Performance is likely better with a higher-clocked more modern design with more cores. Verify that the zfs checksum algorithm you are using is a low-cost one and that you have not enabled compression or deduplication. You did not tell us how your zfs pool is organized so it is impossible to comment more. 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
