[NTLUG:Discuss] 2GB+ file sizes

[cbbrowne@godel.brownes.org]

On Thu, 21 Oct 1999 17:06:02 CDT, the world broke into rejoicing as
Steve Baker <sjbaker1 at airmail.net>  said:
> S Jackson wrote:
> > 
> > Do any of ya'll know where I can get some more info about the 2GB file
> > size limitation in Linux?  Is the VFS going to be updated in 2.4 to
> > support large files?  Are there currently any patches I can apply to use
> > big files?  I'm trying to integrate Linux into a production environment,
> > and this is a big stumbling block (although our current OS, SCO
> > Openserver, has the same problem).  Please, if you have any info let me
> > know.  Thanx.
> 
> SGI announced that they had freed up the source for their XFS filing
> system for Linux use - that can do >2Gb - but I don't know whether
> anyone has actually ported that system across to Linux yet. SGI's
> XFS is *very* cool.  You can do neat stuff like telling the OS
> that a particular process needs (say) 30% of the disk bandwidth,
> and the filing system will hold off other processes from accessing
> the disk in order to keep that proportion of the bandwidth free.
> 
> As another *wild* thought.  Can DOS file systems have >2Gb files?
> If so, you could format your large partition as a DOS drive (yuk,
> ack!) and mount it under Linux.  I have no idea if that would
> work.

The "XFS solves the 2GB problem" is a commonly believed fallacy.  It
is not actually the case.

I was at the talk last week in Atlanta at ALS by the guys at SGI that
are working on the XFS project.  I put a direct question about the
infamous "2GB limit" to Jim Mostek, asking if XFS did anything about
the limitations of file size by VFS on 32 bit systems.

As I expected, he indicated that XFS does not affect the 32 bit limit
at the VFS level.  (The question was asked so that I could have a good
quote from someone who writes filesystems for a living to address the
fallacy.)

The 32 bit limit on file size is no longer, even for EXT2, an issue
that relates to the filesystem.  EXT2 can already support 2TB files on
64 bit systems.  Any filesystem that uses the standard VFS interface is
limited to 32 bit __offset values on IA-32 systems.

By the way, based on the SGI discussions at ALS, I wouldn't expect to
see an XFS release until next year.
--
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