On Mon, Aug 11, 2008 at 6:08 AM, Henrik <henke@mac.se> wrote:
> 11 aug 2008 kl. 12.35 skrev Glyn Astill:
>
>>>>
>>>>> It feels like there is something fishy going on.
>>>
>>> Maybe the RAID 10
>>>>>
>>>>> implementation on the PERC/6e is crap?
>>>>
>>
>> It's possible. We had a bunch of perc/5i SAS raid cards in our servers
>> that performed quite well in Raid 5 but were shite in Raid 10. I switched
>> them out for Adaptec 5808s and saw a massive improvement in Raid 10.
>
> I suspected that. Maybe I should just put the PERC/6 cards in JBOD mode and
> then make a RAID10 with linux software raid MD?
You can also try making mirror sets with the hardware RAID controller
and then doing SW RAID 0 on top of that. Since RAID0 requires little
or no CPU overhead, this is a good compromise because the OS has the
least work to do, and the RAID controller is doing what it's probably
pretty good at, mirror sets.