Re: File Limits

[Paul Crawford <psc@sat.dundee.ac.uk>]

Dear Xavier,
Traditionally most UNIX / C language applications used a 32-bit signed 
integer for file offset operations, hence the 2GB limit. This applied 
even to DOS 16-bit applications as they also supported 32-bit 'long' 
integers by special arithmetic.

You can get 32-bit applications that support >2GB because they are using 
special arithmetic to implement 64-bit offsets, but that is of course 
the 'natural' size for 64-bit applications.

At the time this was started 2GB was huge! When DOS was first available 
in the early 1980s you could only get 10MB or so HDD. It was only around 
1995 that you could get a consumer product HDD with 2GB capacity, let 
alone consider single files of greater than this. And now my PC has 8GB 
of memory!

Even today, the likes of fat32 has the problem that a large file (e.g. 
video or backup archive, etc) can cause a write error if it exceeds 4GB.

Regards,
Paul

On 18/01/11 14:16, Xavier Tarifa wrote:
>> The standard limits for 32-bit Linux programs is 2GB per file, even
>> though ext3 allows much, much more total space (and file size).
>
>> Have you tried using a 64-bit Linux and matching dosemu version?
>
> You're right, a 64-bits linux does work. I would have never thought
> that there was such a low limitation, though. It's the first program
> I can think of that I've found problems with big files (but the only
> other big files that I've used are mainly backups and vídeos so not a
> lot of apps involved).
>
> Thanks a lot, that would have been probably the last reason I would
> think of.



-- 
Dr. Paul S. Crawford
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Dundee University
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Email: psc@sat.dundee.ac.uk
The University of Dundee is a Scottish Registered Charity, No. SC015096
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