[Beowulf] network filesystem

[Angel de Vicente]

Hi,

> I have a small (16 dual xeon machines) cluster. We are going to add
> an additional machine which is only going to serve a big filesystem via
> a gigabit interface.
> 
> Does anybody knows what is better for a cluster of this size, exporting the
> filesystem via NFS or use another alternative such as a cluster filesystem
> like GFS or OCFS?

If you have a well-defined set of applications to run in this cluster, you can
probably perform some benchmarks and make a more informed decission. If, like
us, you don't know in advance what sort of applications you will be running in
the cluster, you could have this extra node as a NFS server for /home and
/scratch and install a parallel file system as well. This is what we have, with
PVFS2, which for some users is just convenient (suddenly they think we bought a
4TB disk), and for some others is down to speed. They decide whether to use NFS
or PVFS.

We were hammering for weeks at PVFS in a test cluster without a glitch, but in
any case I tell our users to not store in PVFS anything that they could not
easily recreate. It is quite stable these days, but we don't have RAIDs or HA
stuff for the PVFS servers, so if one is down the whole thing suffers.

Cheers,
Angel de Vicente