On Mon, Aug 17, 2009 at 5:06 PM, <en...@businessgrade.com> wrote: > Quoting en...@businessgrade.com: > >> Quoting Ross Walker <rswwal...@gmail.com>: >> >> >> >>> Check that each disk's read cache is enabled with format -e <drive>, >>> cache, read_cache, display. >>> >>> -Ross >> >> Thanks Ross. Did that early on. Read cache is enabled for all drives >> >> > > Any other thoughts or suggestions? Does anyone have similar hardware to > mines? > > http://www.supermicro.com/products/chassis/2U/216/SC216E2-R900LP.cfm > http://www.supermicro.com/products/motherboard/Xeon1333/5400/X7DWN+.cfm > http://www.supermicro.com/products/accessories/addon/AOC-USASLP-L8i.cfm > > Again, I have 12 Seagate 10K SAS drives and a Intel X25-E
What IO size was your dd command? What was the zfs recordsize, default 128K? Maybe your expecting too much? With prefetch (read-ahead) disabled each io is going direct to disk, and with a dd command (only single outstanding io at a time) and no read-ahead you will see around a single disk's performance. Try re-enabling prefetching. -Ross _______________________________________________ storage-discuss mailing list storage-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/storage-discuss
