Compaq Proliant CISS slow writes
Philippe.Pegon at crc.u-strasbg.fr
Sun Feb 5 03:05:25 PST 2006
Ivan Voras wrote:
> I need to get a Proliant machine with 2 P3 processors running FreeBSD 6.
> I don't know much about the machine, I think it's ML 380 G2 or close to
> that, but I have physical access. So far, everything is fine (once the
> inability to boot from CD-ROM is circumvented), except one "detail":
> horrible write performance on its CISS 5 RAID5 array. I get ~75MB/s
> burst (large blocks) reads, and only 5MB/s burst writes. I know how
> RAID5 works, but still, this is bad. The machine has been running Linux
> before this and performance was Ok - I didn't benchmark it but the
> "feeling" when working on it was normal, while on FreeBSD it's noticably
> slow in mixed read/write load.
> Is there anything I can try to improve this? In the verbose boot log
> there's a line that says the controller supports "simple, performant and
> MEMQ" modes, and the one that's used is "simple" - does this have any
> influence? If so, how to change it?
do you have write cache on your Smart Array 532 ?
I had the same problem last year with a Smart Array 642, this controller
is sold without write cache and we needed to buy the couple
battery/write cache for it to have good write performance.
More information about the freebsd-stable