[Unionfs] problems with NFS export, v. 1.4

[Josef Sipek]

On Wed, Nov 22, 2006 at 11:51:20AM +0100, Michael Creel wrote:
> Hello to everyone,
> 
> I'm adapting the ParallelKnoppix live CD to export home to the compute 
> nodes via unionfs. This makes things very convenient, since a uniform 
> set of files is available to all the nodes in the cluster. One the 
> master node, the home dir is /UNIONFS/home/pk. This is nfs exported to 
> the nodes using the following entry in /etc/exports:
> 
> /UNIONFS/home/pk 
> 192.168.0.0/255.255.255.0(rw,root_squash,fsid=42,async,no_subtree_check)
> 
> 
> This works fine with a 2.6.17 kernel and unionfs 1.3. However, with a 
> 2.6.18 kernel and unionfs 1.4, the compute nodes can't mount the 
> export, and the report the typical "reason given by server: permission 
> denied" error. So I'm looking for pointers as to how to get this going 
> with unionfs 1.4 (or I can switch to a 2.6.19 kernel and unionfs CVS, 
> if that would help).
 
If you don't mind runing latest kernels, using CVS snapshots is better. In
this case, there haven't been any changes since the 1.4 release (mostly due
to the fact that it was a rather late release.)

Besides that, it is really odd that it doesn't work with 2.6.18. Looking at
the Unionfs changelog I don't see anything that would make it not work like
that. We'll try to reproduce it here in the lab...
 
> I can supply details, if that would help. Also, though it'a a big 
> download, there are 2 iso images at 
> http://pareto.uab.es/mcreel/ParallelKnoppix/download/testing/
> The one with "good" in the name is the working version with unionfs 
> 1.3 and kernel 2.6.17, the other uses unionfs 1.4 and kernel 2.6.18.2, 
> and it doesn't work.

This should help.

Thanks,

Josef "Jeff" Sipek.

-- 
NT is to UNIX what a doughnut is to a particle accelerator.