Re: Promise PDC20376

["David Ellingsworth" <david@identd.dyndns.org>]

>  > Since I put this out there, I felt it was important to follow-up on so
>  > others could benefit from my experiences. After extensive testing, the
>  > cause of the problems I've experienced are a result of a bug in the
>  > Fasttrak bios for the Promise 376 controller. Specifically speaking,
>  > bios interrupt 13h, AH=42 fails to read the requested sector from the
>  > drive despite the fact that bios interrupt 13h, AH=41, BX=0x55AA
>  > indicates the drive supports LBA extensions. The only known
>  > work-around at this time is to limit the size of the primary boot
>  > partition to 8GB or less and place it below the 8GB boundary where LBA
>  > extensions are not required to read the drive. I have contacted
>  > Promise concerning this issue and will provide more updates if
>  > anything metabolizes. Until then any users experiencing similar issues
>  > should use the work-around I've described above to boot the operating
>  > system of their choice.
>
> For booting with grub only /boot needs to be accessible by the BIOS,
> so it's common to make /boot a separate partition early on the disk
> with / and other partitions higher up.
>
> This is the first I've heard of any Promise SATA controller having
> such lame limitations.
>

A small update to this. It seems the above mentioned interrupt fails
somewhere around the 128GB boundary. Interrupt 13h, AH=42 uses a 64
bit sector address and should be capable of addressing the entire
drive. For a SATA controller, this limitation seems relatively
arbitrary. For IDE controllers, a limitation such as this is
apparently common.

Regards,

David Ellingsworth