64-bit raid controller recommendation

[Scott Long]

Luoqi Chen wrote:
>>Luoqi Chen wrote:
>>
>>>Hi,
>>>
>>>I'm setting up a Supermicro 7043P-8R box with 8G of memory and
>>>I've just found out that the Adaptec 2010S ZCR card didn't support
>>>64-bit addressing (being i2o based). So I'm looking for a card
>>>that could directly (no bouncing) address at least 8G physical
>>>memory, does anyone have any recommendation?
>>>
>>
>>It's hard to tell from the asr driver where the 32-bit limitation
>>comes from and/or if there is a way to fix it.  To directly answer
>>your question, the Adaptec aac cards and driver support 64-bit
>>addressing with no bouncing.  This includes the 5400, 2120, and 2200
>>cards.
>>
>>Scott
>>
> 
> The 32-bit limitation seems to come from the i2o architecture. I've
> checked with the linux driver, there's no 64-bit support either. The
> telltale sign is in the marketing literature it is NOT mentioned as
> IA-64 ready.

The information that I've seen in the dpti2o headers leaves me to
believe that while the command data structures might be limited to the
first 4GB, the data buffer s/g lists are not inherently limited by
anything other than the firmware.  Academic difference, though.

> 
> The Adaptec 2200 sounds like a good fit for my need. How complete is
> the 64-bit support? Do you have any plan to back port it to -stable?
> (In)Stability makes me reluctant to install 5.x in a production system.
> I'm willing to do the back-porting if you don't have time. I've already
> done quite a few back-porting to be able to use 8G of memory.

The 5.x driver is fully 64-bit capable for data buffers (the firmware
limits command structures to the lower 4GB) and has been tested under
PAE.  I have no intention to backport to 4.x as there is no need for
64 bit support there.  If you have PAE support in 4.x then I'd be happy
to help you backport the 64 bit aac work.

Scott