Please look the "load" in the top.The CPU idle time is not enough.The difference is very huge.In your case may be the load over the "2".If am I right then your CPU is weak for this feature. Check again. Brogyi
2013/2/20 Reginald Beardsley <[email protected]> > On an N40L running oi_151a7 w/ four ST2000DM001 drives I'm seeing a large > drop in performance for RAIDZ2 vs RAIDZ1 which surprises me. > > The discussions google found were not entirely enlightening and not OI > based. How much CPU does a small OI based ZFS server need? > > For 3 disk RAIDZ1 I get 189-199 MB/s and 179 MB/s for 4 disk RAIDZ1. But > for 4 disk RAIDZ2 I get 109-118 MB/s. I expected some loss in performance, > but not that much. These are measured writing 64 GB of /dev/zero to the > RAIDZ filesystem from a console window. > > For a 256 GB file I got 111 MB/s writing and 279 MB/s reading 4 disk > RAIDZ2. > > System is unloaded w/ 4 GB of ECC DRAM using a 4-way mirror rpool in the > s0 slices w/ RAIDZ in the s1 slices. > > Does the drop in RAIDZ2 write performance correspond to other people's > experience? If so, why such a large hit? top suggests the system has spare > CPU capacity (30-50% idle). For my current needs things look good, but I'd > like to understand why a bit better. Or if there is some tuning I should > do. > > Have Fun! > Reg > > _______________________________________________ > OpenIndiana-discuss mailing list > [email protected] > http://openindiana.org/mailman/listinfo/openindiana-discuss > _______________________________________________ OpenIndiana-discuss mailing list [email protected] http://openindiana.org/mailman/listinfo/openindiana-discuss
