Re: What to do about the 2TB limit on HDIO_GETGEO ?

[Ric Wheeler <ric@emc.com>]

Mark Lord wrote:
> Linus Torvalds wrote:
>>
>> On Mon, 24 Mar 2008, Mark Lord wrote:
>>> The return value uses "unsigned long",
>>> which on a 32-bit system limits drive offsets to 2TB.
>>
>> One relevant question is: does anybody seriously care about the 
>> combination of "32 bit" and "huge modern drives" any more?
>>
>> Sure, we can add a 64-bit version that ends up being used only on 
>> 32-bit systems, but quite frankly, I think the solution here is to 
>> just ignore the issue and see if anybody really even cares.
>>
>> Because quite frankly, the kind of people who buy modern 2TB drives 
>> generally don't then couple them to CPU's that are five+ years old.
> ..
> 
> Yeah.  Except Dell will undoubtedly have them in desktops
> within 2 years, and tons of people (myself included) still use
> 32-bit (K)Ubuntu on our systems, simply for the better binary 
> compatibility that it is perceived to give with things like
> browser plugins and stuff.

I think that there are many embedded applications (lots of them linux based)
which have large amounts of storage behind low power, low cost 32 bit CPU's.

Think of the home/small office NAS boxes that you can get from bestbuy or other 
big box stores. Those devices today have 4 S-ATA drives (each of which can be 
1TB in size).

Also, if you have a very low end box, it can still access really large storage
over iSCSI or a SAN which will present as a local, large device.

Over time, even these low end CPU's will migrate towards 64 bits, but we are not
there yet...

ric