pdc type metadata location on disk

[Heinz Mauelshagen]

James,

thanks for the heads up.

We do have heuristics for a bunch of possible PDC metadata offsets but
things like HPA and new offsets found keep adding to the given list.

I've already thought of scanning the end of each device for any PDC
signature rather than going by finite list of possible assumed ones.

Probably adding such approach to a later release...

Regards,
Heinz

On Tue, 2009-09-22 at 17:12 -0400, James Olson wrote:
> Hi Heinz, 
> dmraid sometimes fails to find promise pdc metadata. I have analyzed
> the failure and have figured out that the simple offset from the end
> of the disk is not enough. The metadata is in the beginning of what
> the controller thinks is the last cylinder of the disk. If you examine
> the dmraid -n output, 0x22b raid.sectors: 63, in this case the place
> to look for the metadata is near the end of the disk but a in sector
> number divisible by 63. I have worked around this problem by adjusting
> the host protected area using hdparm, but this is not an ideal
> solution. 
> Let me know if you want more details, 
> -James 
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