filesystem performance

Mark Wong markwkm at
Wed May 6 15:03:01 UTC 2009

On Wed, May 6, 2009 at 7:18 AM, Florian Smeets <flo at> wrote:
> On 05.05.09 07:30, Mark Wong wrote:
>> Hi everyone,
>> We (PostgreSQL community) have a HP DL380 G5 that we were using to do
>> some very basic filesystem characterizations as part of a database
>> performance tuning project, so we wanted to give FreeBSD a try out of
>> the box.  For this set of data we used 7.1.  We're (us few that are
>> running the tests) are fairly unfamiliar with the community here, so
>> I'll be as brief as I can.  We're basically wondering if the data
>> we're getting out of the box is expected, and any tuning guidelines
>> including what changes we should expect to see in the performance.
> I guess you are using the ciss driver in this box? There was a performance
> regression in this driver in 7.1. This should be fixed in 7.2, which came
> out recently. It is believed that you should get a whole lot better IO
> performance with 7.2 if you are using the ciss driver.
> From the 7.2 release notes:
> A bug in the ciss(4) driver which caused low “max device openings” count and
> led to poor performance has been fixed.

We'll have to make time to try that. :)  Thanks (and to the others)
for pointing that out.


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