On Tue, 2011-01-18 at 15:11 +0000, Michael Armstrong wrote: > I've since turned off dedup, added another 3 drives and results have improved > to around 148388K/sec on average, would turning on compression make things > more CPU bound and improve performance further? > > On 18 Jan 2011, at 15:07, Richard Elling wrote: > > > On Jan 15, 2011, at 4:21 PM, Michael Armstrong wrote: > > > >> Hi guys, sorry in advance if this is somewhat a lowly question, I've > >> recently built a zfs test box based on nexentastor with 4x samsung 2tb > >> drives connected via SATA-II in a raidz1 configuration with dedup enabled > >> compression off and pool version 23. From running bonnie++ I get the > >> following results: > >> > >> Version 1.03b ------Sequential Output------ --Sequential Input- > >> --Random- > >> -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- > >> --Seeks-- > >> Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP > >> /sec %CP > >> nexentastor 4G 60582 54 20502 4 12385 3 53901 57 105290 10 > >> 429.8 1 > >> ------Sequential Create------ --------Random > >> Create-------- > >> -Create-- --Read--- -Delete-- -Create-- --Read--- > >> -Delete-- > >> files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec > >> %CP > >> 16 7181 29 +++++ +++ +++++ +++ 21477 97 +++++ +++ +++++ > >> +++ > >> nexentastor,4G,60582,54,20502,4,12385,3,53901,57,105290,10,429.8,1,16,7181,29,+++++,+++,+++++,+++,21477,97,+++++,+++,+++++,+++ > >> > >> > >> I'd expect more than 105290K/s on a sequential read as a peak for a single > >> drive, let alone a striped set. The system has a relatively decent CPU, > >> however only 2GB memory, do you think increasing this to 4GB would > >> noticeably affect performance of my zpool? The memory is only DDR1. > > > > 2GB or 4GB of RAM + dedup is a recipe for pain. Do yourself a favor, turn > > off dedup > > and enable compression. > > -- richard > > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Compression will help speed things up (I/O, that is), presuming that you're not already CPU-bound, which it doesn't seem you are. If you want Dedup, you pretty much are required to buy an SSD for L2ARC, *and* get more RAM. These days, I really don't recommend running ZFS as a fileserver without a bare minimum of 4GB of RAM (8GB for anything other than light use), even with Dedup turned off. -- Erik Trimble Java System Support Mailstop: usca22-317 Phone: x67195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
