Re: SAS Raid10 vs SATA II Raid10 - many small reads and writes

On Thursday, March 11, 2010, Phillip Berry <pberry(at)stellaconcepts(dot)com> wrote:
> On Wednesday 10 March 2010 18:32:41 Scott Marlowe wrote:
>> On Tue, Mar 9, 2010 at 11:49 PM, Phillip Berry
>>
>> <pberry(at)stellaconcepts(dot)com> wrote:
>> > Hi Everyone,
>> >
>> > We're in the market for a new DB server to replace our current one (yes
>> > it's one of *those* questions) ;).
>> >
>> > It'll have quad core Xeons, 36GB RAM and some sort of Raid 10
>> > configuration.
>> >
>> > Our provider is pushing us towards 6 x SATA II disks in a Raid 10
>> > configuration or 4 x SAS disks in Raid 10 (budget constraints).
>>
>> Are those your only two options?  No 6 SAS drives?  Are you looking at
>> 7200rpm or 10krpm SATA?  15krpm or 10krpm SAS?  What RAID controller?
>> Battery backed Cache?  Software RAID?
>>
>
> They're charging  a lot more for SAS than for SATA so it's a budget constraint. And we can only fit
> six drives in the machine so that limits the number of drives for the SATA option.
>
> Hardware raid controller for both options, but I'm not sure what brand (yet).
>
> 15,000rpm SAS
> 10,000rpm SATA
>
>
> As with everything it's a trade off: 4 SAS drives or 6 SATA II drives in raid 10. I'm trying to find
> out if (for many many small reads and writes) one is more desirable than the other.

How much do you have to cut your CPU and/or memory (CPU first!) to get
to 6 SAS? It may be well worth considering....

--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/