>I think the main difference is that the WAL activity is mostly linear, where the normal data activity is rather random access. That was what I was expecting, and after reading http://www.pcguide.com/ref/hdd/perf/raid/concepts/perfStripe-c.html I figured that a different stripe size for the WAL set could be worth investigating. I have now dropped the old sets (10+18) and created two new raid1+0 sets (4 for WAL, 24 for data) instead. Bonnie++ is still running, but I'll post the numbers as soon as it has finished. I did actually use different stripe sizes for the sets as well, 8k for the WAL disks and 64k for the data. It's quite painless to do these things with HBAnywhere, so it's no big deal if I have to go back to another configuration. The battery cache only has 256Mb though and that botheres me, I assume a larger (512Mb - 1Gb) cache would make quite a difference. Oh well. >Btw, it may make sense to spread different tables or tables and indices onto different Raid-Sets, as you seem to have enough spindles. This is something I'd also would like to test, as a common best-practice these days is to go for a SAME (stripe all, mirror everything) setup.
