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

On Thu, Feb 5, 2009 at 6:10 PM, Matt Burke <mattblists@icritical.com> wrote:
> 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...

Where exactly is there  limitation of 32 drives.
the datasheet of 1680 states support upto 128drives
using enclosures.

regds
rajesh kumar mallah.

>
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