On Wed, Jul 23, 2008 at 1:57 PM, Jeffrey Baker <jwbaker@xxxxxxxxx> wrote: > On Tue, Jul 22, 2008 at 5:32 PM, Scott Marlowe <scott.marlowe@xxxxxxxxx> wrote: >> On Tue, Jul 22, 2008 at 6:04 PM, Jeffrey W. Baker <jwbaker@xxxxxxxxx> wrote: >> >>> Strangely the RAID controller behaves badly on the TPC-B workload. It >>> is faster than disk, but not by a lot, and it's much slower than the >>> other flash configurations. The read/write benchmark did not vary when >>> changing the number of clients between 1 and 8. I suspect this is some >>> kind of problem with Areca's kernel driver or firmware. >> >> Are you still using the 2.6.18 kernel for testing, or have you >> upgraded to something like 2.6.22. I've heard many good things about >> the areca driver in that kernel version. > > These tests are being run with the CentOS 5 kernel, which is 2.6.18. > The ioDrive driver is available for that kernel, and I want to keep > the software constant to get comparable results. > > I put the Samsung SSD in my laptop, which is a Core 2 Duo @ 2.2GHz > with ICH9 SATA port and kernel 2.6.24, and it scored about 525 on R/W > pgbench. From what I've read the scheduler in 2.6.24 has some performance issues under pgsql. Given that the 2.6.18 kernel driver for the areca card was also mentioned as being questionable, that's the reason I'd asked about the 2.6.22 kernel, which is the one I'll be running in about a month on our big db servers. Ahh, but I won't be running on 32 Gig SATA / Flash drives. :) Wouldn't mind testing an array of 16 or so of them at once though.
