Large Files on IA32

Jakob Østergaard jakob at unthought.net
Sun Jul 29 19:46:39 EDT 2001


On Sun, Jul 29, 2001 at 04:18:48PM -0400, Donald Becker wrote:
> On Sat, 28 Jul 2001, [iso-8859-1] Jakob Østergaard wrote:
> 
> > The 2GB limit is *not* within ext2.  If the filesystem is all you change, the
> > 2GB limit will stay.
> > 
> > The limitation is in VFS, the virtual file-system layer on top of *any*
> > filesystem you put in Linux.
> 
> This is incorrect.

Ok, let me re-phrase:  "The limitation is"  ->  "There is a limitation"

What I wanted to say was:  Just changing the FS won't do it.  I didn't mean to
say "fixing VFS alone will solve all the problems in the world".  I'm sorry if
it came out that way    :)

....
> 
> > The 2.4 kernels do not have this limitation anymore.
> 
> The 2.4 kernels have the same 32 bit block offset limit.

Now what does that mean ?

[root at phoenix /backup]# uname -a 
Linux phoenix 2.4.7 #1 SMP Sat Jul 21 17:32:55 CEST 2001 i686 unknown
[root at phoenix /backup]# ll stuff_here 
-rw-r--r--    1 root     root     3153758271 Jul 30 01:36 stuff_here

Stock 2.4 kernel fresh off kernel.org, files in excess of 2GB no problem.

Assuming the limitation is there, what exactly does that mean to us ?  :)

> 
> >  Files larger than 2 GB will work on 32-bit platforms on Linux 2.4 on
> > any filesystem that supports it (including, of course, ext2).
> 
> The kernel isn't the real issue -- doing that part of the code is easy
> and centralized.  A large part of the work was in the library and utility
> support.

Absolutely - the kernel is a necessary part but not sufficient in itself.

Lots of int's to work on in legacy code    :)

> 
> 
> Donald Becker				becker at scyld.com
> Scyld Computing Corporation		http://www.scyld.com
> 410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
> Annapolis MD 21403			410-990-9993
> 

-- 
................................................................
:   jakob at unthought.net   : And I see the elder races,         :
:.........................: putrid forms of man                :
:   Jakob Østergaard      : See him rise and claim the earth,  :
:        OZ9ABN           : his downfall is at hand.           :
:.........................:............{Konkhra}...............:

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