Re: ATARAID/FakeRAID/HPTRAID/PDCRAID as dm targets?

[Jeff Garzik <jgarzik@pobox.com>]

Carl-Daniel Hailfinger wrote:
> Jeff Garzik wrote:
> 
>>Carl-Daniel Hailfinger wrote:
>>
>>
>>>Wilfried Weissmann wrote:
>>>
>>>
>>>>Arjan van de Ven wrote:
>>>>
>>>>
>>>>
>>>>>On Sat, Mar 20, 2004 at 07:23:01PM -0700, Kevin P. Fleming wrote:
>>>>>
>>>>>
>>>>>
>>>>>>Jeff Garzik wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>So go ahead, and I'll lend you as much help as I can.  I have the
>>>>>>>full Promise RAID docs, and it seems like another guy on the lists
>>>>>>>has full Silicon Image "medley" RAID docs...
>>>
>>>
>>>Jeff: May I request your docs?
>>
>>Unfortunately not, but I can get you in touch with somebody at Promise
>>who can.  They're definitely interested in working with the open source
>>community.  Not public...
> 
> 
> Could you please send me the contact information via private mail?
> Thanks.

Will do.


>>>I'll use your work as a foundation. First step is integrating detection
>>>for non-HPT arrays. If the code looks too messy after that, I still can
>>>refactor it.
>>>
>>>As soon as I have some code to get at least PDCRAID working, I'll post
>>>again.
>>
>>
>>Feel free to ask me questions, too.
> 
> 
> OK. First question: calc_pdcblock_offset calculates the superblock
> location based on capacity, sectors and heads. However, the same machine
> which showed 255 heads under Kernel 2.4 now shows only 16 heads and some
> of the hardcoded location calculation routines may fail. Is there a
> userspace generic method for finding the right sector?
> (It works sometimes for me.)

The standard method one uses to calculate cyl/head/sect in ATA, AFAIK. 
If that changes between 2.4 and 2.6, that sounds like a bug unrelated to 
the code you're writing...

	Jeff