Thanks to everyone for the help on this.
Here is what we have found to date with large file support and Linux.
* you must be running RHat Kernel 2.4.2 (this includes large FS support in ext2)
* you must have an application that supports large FS's (as per Aaron's idea we modified the gzip.c header and recompiled gunzip)
* you need to be mounting with NFS v3 for > 2GB
Thanks to all for the help again..
-----Original Message-----
From: Chris Thompson [mailto:cet1@cus.cam.ac.uk]
Sent: Thursday, March 29, 2001 3:37 AM
To: toasters@mathworks.com
Cc: dhubbard@websense.com; Aaron.Sims@netapp.com;
crandall@matchlogic.com
Subject: Re: File too large ?
Just concentrating on the Solaris parts of this thread...
Dan Hubbard <dhubbard@websense.com> wrote:
>
> We are using a ONTAP v 6.0.1 and are NFS mounting Solaris and Redhat Linux
> boxes. We are in the process of creating some large text files and cannot
> either gunzip and/or create files greater than 2GB's. We have bumped up our
> maxfiles and set the options nfs.v2.df_2gb_lim ON without any luck.
You don't say which version of Solaris you are running. I don't believe
the version of gunzip included in Solaris 8 is large-file-aware.
Charles Randall <crandall@matchlogic.com> wrote:
>
> 1. NFS v2 doesn't support files larger than 2 GB. Switch to NFS v3. Only
> very recently has the Linux NFS implementation supported NFS v3 (see below).
>
> 2. Can you work with files larger than 2 GB using the same tools on a local
> file system? If so, NFS v3 will help. If not, you'll have to find out how to
> "large file enable" your applications. On Solaris, look at the "largefile"
> and "lfcompile" manpages.
It's perhaps worth adding that large file support (i.e. > 2 GB) started
with Solaris 2.6. Some people run amazingly ancient versions of Solaris...
Aaron Sims <Aaron.Sims@netapp.com> wrote:
[ ... NFS v2 comments omitted ... ]
>
> I've seen this before (at least on Solaris) using NFSv3. Some utilities in
> Solaris (like 'ls','tar' etc.) will utilize 32bit versions system calls like
> open(),stat(),read(), etc. In order to do operations on a file larger than
> 2gb, your program must use open64(),stat64(),etc. I've seen Solaris' 'ls'
> command cough up hair balls because the file is larger than 2gb. I ran
> 'truss ls -l largefile' and noticed that 'ls' was using the wrong system
> calls. Although, on that same system, if I used '/usr/ucb/ls' it worked
> just fine. Using 'truss' on '/usr/ucb/ls' showed that it was using the
> correct system calls.
This rather amazes me. Solaris /usr/bin/ls is supposed to have been
large-file-aware right from the start of Solaris 2.6, and I've never
seen it behave as described above since then.
I *have* observed problems with Solaris ls(1) applied to files larger
than 2^40 bytes (the UFS limit) but smaller than 2^43 bytes (the
WAFL limit). Of course, even on a filer such files are necessarily
sparse! That was some time ago, I'll try and repeat the experiment with
up-to-date versions of both Solaris and ONTAP.
> I finally found an answer on how to force your application (I'll assume
> you have source code) to use the 64bit version of the system calls. You
> need to define _FILE_OFFSET_BITS 64 in your source code. That'll force
> your app (under Solaris) to use open64(),stat64(), etc. You might want
> to peruse through your gunzip code to see if it is defined.
This is all described in the lfcompile(5) man page, of course.
Note also that if you are compiling in 64-bit architecture mode (e.g.
-xarch=v9 with the SUNWspro compilers) in Solaris 7 or later, then the
largefile support comes along with it automatically.
> I'm not sure that upgrading to 6.0.1R3 will help if you're using NFSv2.
I don't think it will help if you are using NFSv3 either!
Chris Thompson University of Cambridge Computing Service,
Email: cet1@ucs.cam.ac.uk New Museums Site, Cambridge CB2 3QG,
Phone: +44 1223 334715 United Kingdom.