[Gluster-users] Throughout over infiniband

[Brian Candler]

On Mon, Sep 10, 2012 at 10:03:14AM +0200, Stephan von Krawczynski wrote:
> > Yes - so in workloads where you have many concurrent clients, this isn't a
> > problem.  It's only a problem if you have a single client doing a lot of
> > sequential operations.
> 
> That is not correct for most cases. GlusterFS always has a problem on clients
> with high workloads. This obviously derives from the fact that the FS is
> userspace-based. If other userspace applications eat lots of cpu your FS comes
> to a crawl.

It's only "obvious" if your application is CPU-bound, rather than I/O-bound.

> > [...]
> > Have you tried doing exactly the same test but over NFS? I didn't see that
> > in your posting (you only mentioned NFS in the context of KVM)
> 
> And as I said above NFS (kernel-version) does have no problem at all in these
> scenarios.

I think the OP needs to test the specific workload - I think it was iozone -
using NFS.

I saw figures for iozone local access to disk, and iozone over glusterfs,
but not iozone over NFS.

Regards,

Brian.