2 GB filesize limit on NFS v3 mount from linux to AIX v4.3.3

[Hendrik van Run]

Hi,

I have a problem creating files greater than 2 GB on a NFS v3 mounted
filesystem using AIX v4.3 ML6. (NFS server is linux 2.4.18)

I have a linux machine (hostname nllab010, kernel 2.4.18) with an ext2
filesystem. It supports files larger than 2 GB (which was impossible
using 2.2 or older kernels). I also compiled NFS v3 support into the
kernel, and exported a filesystem for NFS use (using /etc/exports with
this line: "/data           nllab008(rw)").

I mount this filesystem on an AIX 4.3.3 B80 machine (nllab008), while
explicitly using NFS v3. I created the following entry in
/etc/fileystems:

/data/ext:
        dev             = "/data"
        vfs             = nfs
        nodename        = nllab010
        mount           = false
        options         = vers=3,intr
        account         = false

This works fine, until I try to create a file bigger than 2 GB. This
fails. I have set up the ulimit to ulimited for both the client and
the server. The linux ext2 filesystem can store files bigger than 2 GB
(I tried it), and as far as I know NFS v3 explicitly supports 64 bit
file addressing (instead of 32 bit for v2, thus breaking the 2 or 4 GB
barrier).

Do you know what I missed? I really need this to work, we need to use
it for DB2 backups (which are BIG). Perhaps some undocumented AIX
setting?

Please, help me out...

Hendrik

[Alan Jiang]

Hendrik,

I did the similar testing. AIX has 4.3.3ML09 installed. Suse 8.0
professional version
installed on the other end(uname -a shows: Linux linux 2.4.18-4GB #1 Wed Mar
27
13:57:05 UTC 2002 i686 unknown)

On the AIX side, this is what mount shows:

....
linux /export /linux nfs3 Apr 30 15:58
bg,hard,intr,rw
...

On AIX and Linux, ulimit on file are both set to unlimited.

On AIX side, I did this: dd if=/dev/zero of=/linux/test.f bs=4k
count=537109( about 2.2 GB).

I can see the testing finishing successfully.

If you familiar with kernel trace and iptrace on AIX, you can figure it out
very quickly.

regards,

Alan Jiang

"Hendrik van Run" <r...@phys.uu.nl> wrote in message
news:6c167ec5.02050...@posting.google.com...

[Hendrik van Run]

Thanks Alan, but I already did some experimenting myself... however I
managed to solve the problem now...

Or - in fact - was already solved... it appears that files created
before installing the new kernel (upgraded from 2.2.19 to 2.4.18)
cannot be enlarged beyond the 2 GB limit using NFS v3. On the local
ext2 filesystem this is not a problem.

So, to summarize...

You can mount a linux filesystem on AIX for use of large files (>
2GB). However, I found the following requisites:

- use NFS v3 (supports 64 bits file addressing)
- use linux kernel 2.4 or above (I used 2.4.18)
- use an ext2 filesystem on linux
- use an AIX version with NFS v3 support (I used AIX 4.3.3 ML 6)

I hope this can help others now or in the future.

Hendrik
 

"Alan Jiang" <aji...@nameisalan.net> wrote in message news:<3cd36938$1...@nopics.sjc>...