Re: support for drives larger than 2TiB

From: Greg Freemyer
Date: Sat Jul 24 2010 - 17:39:12 EST


On Sat, Jul 24, 2010 at 2:40 PM, Yuhong Bao <yuhongbao_386@xxxxxxxxxxx> wrote:
>
>> However, 2TiB limit is
>> inherent in the BIOS programming interface and currently the only way
>> to overcome it is using a completely different BIOS interface (EFI,
>> that is).
> Nope, look at the Int13 extensions, it already support 64-bit LBA.
>
> Yuhong Bao

64-bit LBA? I assume you meant 48-bit LBA from ATA-7. It will
address up to PBs I believe. (KB, MB, GB, TB, PB, ....)

But I've seen lots of "48-bit LBA" supporting controllers that hit
limits at 500GB, 1TB, etc. and needed new firmware updates.

Secondly, if you look at the table on the right of
http://en.wikipedia.org/wiki/Master_boot_record#Disk_partitioning you
see that the starting sector of a partition is defined with a 32-bit
value.

ie. 2TB with 512 byte sectors.

The normal solution is to move to a GPT which requires EFI if you want
to boot from it.

Greg
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