[Beowulf] Putting /home on Lusture of GPFS

[Jason Riedy]

And Bill Wichser writes:
> We too have debated this.  Seems a waste to add some 8 or 20 T to a
> local cluster when we have this nice, central filesystem
> available.

Ah, but now we also have the filesystem-storage split...  I'm
contemplating using a single object pool (possibly Ceph) to
provide both a slice for NFS /home and slices & pools for project
storage.  The reasons are more economic than performance or even
management.  The funding model is similar to "buy nodes for a
cluster, get proportional access."  If I can convince people to
add a little overhead, then everyone gains some replication,
etc...

But, really, our current network setup is the limiting factor in
back-of-the-envelope performance estimates.  And I'm the limiting
factor in the whole thing, as our system staff is, um, stretched
thin.