[Lustre-discuss] poor lustre wan performance

[Isaac Huang]

On Tue, Nov 10, 2009 at 08:02:03AM -0500, Dardo D Kleiner - CONTRACTOR wrote:
> ......
> At this point it clearly doesn't matter if I mess with max_rpcs_in_flight which used
> to be a way to mitigate the high BDP.
> 
> Are there new parameters and/or tunings for ko2iblnd we're supposed to be using?  Did
> something change with 1.8.1.1 in this regard - I'm trying to determine if it was our
> move to SLES11 or something else?  Our operational deployment is not yet at this
> latest version but are wary to upgrade since I've indicated I'm having problems.

As far as I know, there's been no change to the ko2iblnd since the
map_on_demand feature which you're already using.

Though it might seem likely that somehow Lustre services were not
creating enough RPCs to keep the pipe full, it'd be easy and quick to
run a LNet selftest to narrow it down (if you haven't done so
already). If a bulk write test from the same client nodes to the same
server nodes results in similar figures, then we'd certainly look at
LNet/ko2iblnd.

Thanks,
Isaac