I've switched to using FIO. Bonnie in my experience produces poor results and is better suited to testing desktop/workstation type load. Most of its tests don't apply to how postgres writes/reads anyway. IOZone is a bit more troublesome to get it to work on the file(s) you want under concurrency and is also hard to get it to avoid the OS file cache. On systems with lots of RAM, it takes too long as a result. I personally like it better than bonnnie by far, but its not flexible enough for me and is often used by hardware providers to 'show' theier RAID cards are doing fine (PERC 6 doing 4GB /sec file access -- see! Its fine!) but the thing is just testing in memory cached reads for most of the test or all if not configured right... FIO with profiles such as the below samples are easy to set up, and they can be mix/matched to test what happens with mixed read/write seq/rand -- with surprising and useful tuning results. Forcing a cache flush or sync before or after a run is trivial. Changing to asynchronous I/O, direct I/O, or other forms is trivial. The output result formatting is very useful as well. I got into using FIO when I needed to test a matrix of about 400 different tuning combinations. This would have taken a month with Iozone, but I could create my profiles with FIO, force the OS cache to flush, and constrain the time appropriately for each test, and run the batch overnight. #---------------- [read-rand] rw=randread ; this will be total of all individual files per process size=1g directory=/data/test fadvise_hint=0 blocksize=8k direct=0 ioengine=sync iodepth=1 numjobs=32 ; this is number of files total per process nrfiles=1 group_reporting=1 runtime=1m exec_prerun=echo 3 > /proc/sys/vm/drop_caches #-------------------- [read] rw=read ; this will be total of all individual files per process size=512m directory=/data/test fadvise_hint=0 blocksize=8k direct=0 ioengine=sync iodepth=1 numjobs=8 ; this is number of files total per process nrfiles=1 runtime=30s group_reporting=1 exec_prerun=echo 3 > /proc/sys/vm/drop_caches #---------------------- [write] rw=write ; this will be total of all individual files per process size=4g directory=/data/test fadvise_hint=0 blocksize=8k direct=0 ioengine=sync iodepth=1 numjobs=1 ;rate=10000 ; this is number of files total per process nrfiles=1 runtime=48s group_reporting=1 end_fsync=1 exec_prerun=echo 3 >sync; /proc/sys/vm/drop_caches On 4/9/09 10:41 PM, "Josh Berkus" <josh@xxxxxxxxxxxx> wrote: > All, > > Wow, am I really the only person here who's used IOZone? > > -- > Josh Berkus > PostgreSQL Experts Inc. > www.pgexperts.com > > -- > Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance > -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
