LinuxSA Mailing list archives

  From: Mike Andrew <mikero@norfolk.nf>
  To  : Linux SA <linuxsa@linuxsa.org.au>
  Date: Mon, 26 Jun 2000 13:23:37 +1130

Re: More space required

On Mon, 26 Jun 2000, David Drury wrote:
> 
> The actuall maximum partition size I think measures in the TerraBytes (but
> I don't have the exact figure).


all hard disks, scsi and ide, work on 32 bits of logical sectors. Each sector
is 512 bytes making the current addressable limit for any drive 2 TeraBytes.

Scsi has always understood this, (e)ide drives also understand this addressing
but the interace at the host end cripples it due to crappy translation schemes
(large, lba, etc)

>There are various BIOS imposed limits depending upon the age of your PC 
> and BIOS. Originnaly it was 512MB. This was fixed with LBA translation 
> that allowed 4, 8, and now 20 GB to be addressed.

the original limit was 42Meg. 'Large' addressing moved this up to 512, LBA on
IDE moved it to 2 gig and lba on Eide moved it to 8gig. At this point, no
matter which hoop you jump thru, the 24 bits available on the bios int 13h call
are finished and done with. There is no further expansion possible unless you
change the size of a logical sector from 512 bytes. This alone will not remove
the 1023 cylinder limit.

I don't know the new EDD bios limit  (2 Terabyte?). The 20Gig is such an
insignificant increase, it's unlikely to be a checkmark.


-- 
http://linux.nf/stepbystep.htm + mirrors
StepByStep submissions: mikero@norfolk.nf


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