Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller

Arjen van der Meijden wrote:

> Afaik the Perc 5/i and /e are more or less rebranded LSI-cards (they're
> not identical in layout etc), so it would be a bit weird if they
> performed much less than the similar LSI's wouldn't you think?

I've recently had to replace a PERC4/DC with the exact same card made by
LSI (320-2) because the PERCs firmware was crippled. Its idea of RAID10
actually appears to be concatenated RAID1 arrays.

Since replacing it and rebuilding the array on the LSI card, performance
has been considerably better (14 disk SCSI shelf)

> Areca may be the fastest around right now, but if you'd like to get it
> all from one supplier, its not too bad to be stuck with Dell's perc 5 or
> 6 series.

The PERC6 isn't too bad, however it grinds to a halt when the IO queue
gets large and it has the serious limitation of not supporting more than
8 spans, so trying to build a RAID10 array greater than 16 disks is
pointless if you're not just after the extra capacity.

Are there any reasonable choices for bigger (3+ shelf) direct-connected
RAID10 arrays, or are hideously expensive SANs the only option? I've
checked out the latest Areca controllers, but the manual available on
their website states there's a limitation of 32 disks in an array...