Re: OT: Help with performance problems

scott.marlowe wrote:
> On Fri, 23 Apr 2004, Chris Hoover wrote:
>
>
>>DB's on Powervaults 220S using raid 5 (over 6 disks)
>
>
> What controller is this, the adaptec? We've found it to be slower than
> the LSI megaraid based controller, but YMMV.

Wow, really? You got any more details of the chipset, mobo and kernel
driver ?

I've been taken to my wits end wrestling with an LSI MegaRAID 320-1
controller on a supermicro board all weekend. I just couldn't get
anything more than 10MB/sec out of it with megaraid driver v1 OR v2 in
Linux 2.4.26, nor the version in 2.6.6-rc2. After 2 days of humming the
Adaptec mantra I gave in and switched the array straight onto the
onboard Adaptec 160 controller (same cable and everything). Software
RAID 5 gets me over 40MB sec for a nominal cpu hit - more than 4 times
what I could get out of the MegaRAID controller :( Even the 2nd SCSI-2
channel gets 40MB/sec max (pg_xlog :)

And HOW LONG does it take to detect drives during POST....ohhhh never
mind ... I really just wanna rant :) There should be a free counseling
service for enraged sysops.

--

Rob Fielding
rob(at)dsvr(dot)net

www.dsvr.co.uk Development Designer Servers Ltd