Ok, I've done all the tests I plan to complete. For highest performance, it seems:
. The measure I think is the most relevant for typical operation is the fastest random read /write / mix. (Thanks Bob, for suggesting I do this test.) The winner is clearly striped mirrors in ZFS . The fastest sustained sequential write is striped mirrors via ZFS, or maybe raidz . The fastest sustained sequential read is striped mirrors via ZFS, or maybe raidz Here are the results: . Results summary of Bob's method http://nedharvey.com/iozone_weezer/bobs%20method/iozone%20results%20summary. pdf . Raw results of Bob's method http://nedharvey.com/iozone_weezer/bobs%20method/raw_results.zip . Results summary of Ned's method http://nedharvey.com/iozone_weezer/neds%20method/iozone%20results%20summary. pdf . Raw results of Ned's method http://nedharvey.com/iozone_weezer/neds%20method/raw_results.zip From: Edward Ned Harvey [mailto:sola...@nedharvey.com] Sent: Saturday, February 13, 2010 9:07 AM To: opensolaris-disc...@opensolaris.org; zfs-discuss@opensolaris.org Subject: ZFS performance benchmarks in various configurations I have a new server, with 7 disks in it. I am performing benchmarks on it before putting it into production, to substantiate claims I make, like "striping mirrors is faster than raidz" and so on. Would anybody like me to test any particular configuration? Unfortunately I don't have any SSD, so I can't do any meaningful test on the ZIL etc. Unless someone in the Boston area has a 2.5" SAS SSD they wouldn't mind lending for a few hours. ;-) My hardware configuration: Dell PE 2970 with 8 cores. Normally 32G, but I pulled it all out to get it down to 4G of ram. (Easier to benchmark disks when the file operations aren't all cached.) ;-) Solaris 10 10/09. PERC 6/i controller. All disks are configured in PERC for Adaptive ReadAhead, and Write Back, JBOD. 7 disks present, each SAS 15krpm 160G. OS is occupying 1 disk, so I have 6 disks to play with. I am currently running the following tests: Will test, including the time to flush(), various record sizes inside file sizes up to 16G, sequential write and sequential read. Not doing any mixed read/write requests. Not doing any random read/write. iozone -Reab somefile.wks -g 17G -i 1 -i 0 Configurations being tested: . Single disk . 2-way mirror . 3-way mirror . 4-way mirror . 5-way mirror . 6-way mirror . Two mirrors striped (or concatenated) . Three mirrors striped (or concatenated) . 5-disk raidz . 6-disk raidz . 6-disk raidz2 Hypothesized results: . N-way mirrors write at the same speed of a single disk . N-way mirrors read n-times faster than a single disk . Two mirrors striped read and write 2x faster than a single mirror . Three mirrors striped read and write 3x faster than a single mirror . Raidz and raidz2: No hypothesis. Some people say they perform comparable to many disks working together. Some people say it's slower than a single disk. Waiting to see the results.
_______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
