Ross West wrote: >>> IMHO, the default of 16 files is way too low, so needs to be bumped up >>> a lot to like 128 or even more. (-n 128) > >> Good answer, thanks. > > I just remembered of something to note: bonnie++ uses 0 byte files for > it's file tests by default. And they are incredibly fast in the OS - > try adding some data to those files, and it will slow down a _huge_ > amount and you'll get a more normal/realistic reading. > > Also, generally if your %CP reading is in the high 90s, you're seeing > caching (disk or OS) helping out and doing stuff so you'd need to > increase the size of the test. > > Here's a quick run off my machine where you can see that happening for > some values (execution time was roughly 2 min) due to the san system's > caching. > > -= > [bonk ~]$ bonnie++ -n 64:10240:5120 > Version 1.93d ------Sequential Output------ --Sequential Input- > --Random- > Concurrency 1 -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 > bonk 8G 433 99 295605 69 80775 24 801 99 102782 16 926.2 > 34 > Latency 21391us 130ms 627ms 20287us 602ms 302ms > Version 1.93d ------Sequential Create------ --------Random > Create-------- > bonk -Create-- --Read--- -Delete-- -Create-- --Read--- > -Delete-- > files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec > %CP > 64:10240:5120 4239 23 21497 57 89117 91 4089 22 40285 99 98297 > 90 > Latency 607ms 170ms 658us 551ms 3432us 407us
More good info, thanks again. -- Zordrak [email protected] _______________________________________________ Tech mailing list [email protected] http://lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
