[rescue] installing bigger HD in Sun SparcEngine AXe

Meelis Roos mroos at linux.ee
Mon Jun 27 11:32:30 CDT 2005

>> Unless it is ATA133 it will not address more than 137GB (there are a few
>> ATA100 that implement the extension but they are rare).

As noted before, ATA-5/ATA-6 etc are not a requirement.

The specific feature is LBA48. Fir there was C/H/S addressing, then ATA 
got 32-bit LBA (linear) adressing but it had the 128GiB / 137GB limit. 
So they introduced LBA48 to address more sectors (48-bit sector numbers 
- why not 64 at once???) and to use large requests.

An IDE controller can support LBA48 even if it was made before the LBA48 
spec. So far it seems that all IDE controllers are able to address 
beyond 128GiB in PIO modes (at least there is no known 
counter-evidence). But many controllers get confused in DMA mode (state 
machine confused about double write to address register or something 
like that) and don't work in LBA48. Some do work, some don't.

Meelis Roos (mroos at linux.ee)

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