Perc 3 DC - Mailing list pgsql-performance

From Glyn Astill
Subject Perc 3 DC
Date
Msg-id 680067.16755.qm@web23608.mail.ird.yahoo.com
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Responses Re: Perc 3 DC
List pgsql-performance
Hi chaps,

I've had this old card sitting on my desk for a while. It appears to be a U160 card with 128Mb BBU so I thought I'd
wangit in my test machine (denian etch) and give it a bash. 

I set up 4 36Gb drives in raid 0+1, but I don't seem to be able to get more than 20MB/s write speed out of it for large
files(2XRAM usual tests with dd from dev/zero). I don't expect anything great, but I thought it'd do a little better
thanthat. 

I've tried writeback and write through modes, tried changing cache flush times, disabled and enabled multiple PCI
delayedtransactions, all seem to have little effect. 

Finally I decided to wave goodbye to Dell's firmware. LSI has it down as a MegaRAID 493 elite 1600, so I flashed it
withtheir latest firmware.  Doesn't seem to have helped either though. 

Has anybody else used this card in the past?  I'm wondering if this is a driver issue, or if the card is and always was
justcrap? If so I'll proabably try sw raid on it instead. 

Any thoughts?

Glyn




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