Hi, I did a quick test (because I'm curious also). The Hardware was a 3 SATA Disk RaidZ1.
What I did: 1) Create a pool with NexentaStor 3.0.4 (Pool Version 26, Raidz1 with 3 disks) 2) Disabled all caching (primarycache=none, secondarycache=none) to force media access 3) Copied and extracted a recent Linux Kernel to generate meta data intensive workload (lots of small files) 4) Copied the Linux Kernel 10 times Then I booted into SOL11 and did: 5) ran "time du -sh ." on the dataset three times and did the average 6) upgraded the pool to version 31. 7) I rewrote the data (repeated steps 3 and 4). 8) Then I measured the time again (three times average again as in step 5) I did see a ~13% improvement. Here are the numbers: Pool Version 26: ------------------- r...@solaris11:/volumes/mypool# time du -sh . 3.3G . real 1m51.509s user 0m1.178s sys 0m27.115s r...@solaris11:/volumes/mypool# time du -sh . 3.3G . real 1m55.953s user 0m1.128s sys 0m25.510s r...@solaris11:/volumes/mypool# time du -sh . 3.3G . real 1m48.442s user 0m1.096s sys 0m24.405s = 111 Sec Pool Version 31: ---------------- r...@solaris11:/volumes/mypool# time du -sh . 3.3G . real 1m30.376s user 0m1.049s sys 0m21.775s r...@solaris11:/volumes/mypool# time du -sh . 3.3G . real 1m45.745s user 0m1.105s sys 0m24.739s r...@solaris11:/volumes/mypool# time du -sh . 3.3G . real 1m38.199s user 0m1.093s sys 0m24.096s = 97 Sec This means 14 seconds faster, which equals to ~13% of the total 111 secs. I expect even more exciting results for wider raidz and raidz2 arrays. Regards, Robert -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
