[mythtv-users] mythtv + nfs = bad?

Brian Wood beww at beww.org
Thu May 7 14:18:09 UTC 2009

On Thursday 07 May 2009 07:43:38 James Oltman wrote:
> On Wed, May 6, 2009 at 6:55 PM, Brian Wood <beww at beww.org> wrote:
> > What version of NFS?
> >
> > I think NFS v.2 (client side) has a 2GB file size limit, which means it
> > can only look at the first 2GB of a file that's larger than 2GB.
> >
> > Version 3 supports larger files, but obviously it depends on the
> > filesystem on
> > the server side, if it were FAT, for example, a 4.7GB file would be a
> > problem.
> >
> > There is also a limit on the size of a transfer "on the wire", which
> > depends
> > on whether TCP or UDP is used, and the particular implementation.
> >
> > Large files and NFS can be problematical, make sure you understand any
> > limits
> > of your server and client NFS versions, as well as the filesystem in use.
> >
> > Google "nfs file size limits" for more information.
> Brian,
> Thanks for the response.  What was strange about my setup was that it was
> working just fine for a long time.  Then all of the sudden, one day, it
> stopped working.  I don't know if it happened during a kernel update or
> what.  I know I'm running NFSv2.  I don't know how to update myself to v3
> or above.

The precise upgrade method would depend on your distribution, any of the most 
recent distros should have support for v3. I'd consult the relevant support 

Even if (for example) an upgrade to your server side machine enabled nfs v3, 
the systems should negotiate the highest commonly supported version, so if 
your client can only do v2, that's what the server should do as well.

There have also been some changes in the default settings for sync/async, and 
some others I think.

But using "mixed" systems might cause problems.

Another user here noted an improvement in performance by using samba mounts 
instead of NFS, certainly sounds like it's worth a try. I'm going to look 
into that, and try to get some hard numbers.

I'm certainly no expert on NFS, I use it for non-Myth applications and it has 
always "just worked", but I don't put much demand on it. 

beww at beww.org

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