[Beowulf] VMC - Virtual Machine Console

[Gerry Creager]

Ashley Pittman wrote:
> On Wed, 2008-01-16 at 09:18 -0500, Douglas Eadline wrote:
>> I get the desire for fault tolerance  etc. and I like the idea
>> of migration. It is just that many HPC people have spent
>> careers getting applications/middleware as close to the bare
>> metal as possible. The whole VM concept seems orthogonal to
>> this goal. I'm curious how people are approaching this
>> problem.
> 
> There was a paper on this at SC, I don't know if you caught it...
> 
> http://sc07.supercomputing.org/schedule/event_detail.php?evid=11066
> 
> If I was to try and sum it up in one paragraph it would be:
> 
> "The advantages of virtulisation are obvious but for some reason the HPC
> community have been slow to reap these benefits, we predict that this is
> because of a perception that the performance of comms and VM operations
> suffers when virtulised.  This is true however we have demonstrated that
> with months of work this performance loss could be minimised such that
> instead of slowing down performance a lot it would only slow down
> performance a bit."
> 
> I think progress is being made on the comms front, both in terms of raw
> numbers (bandwidth/latency) but also in reducing CPU usage but we are
> still a long way from it being widely used.

I'm constantly reminded of a meeting early on in the SCOOP project, 
which I participate in (http://scoop.sura.org).  "We're able to 
virtualize our model applications using VMware and only see a 13% 
performance hit".  Note that, at this time I was tweaking for ms 
upgrades in MPI communications....

We need to look at virtualization as a means of mitigating, on a 
heterogeneous hardware environment, the concept of porting to every 
different available machine type.  In other words, I think that for a 
grid environment, we might see a lot of benefit for virtualization but 
for a local, homogeneous, cluster, it's less an issue.

By the way: In order to compensate for their "13%" degradation, I had to 
nearly double the number of virtual nodes over real nodes to get the 
same performance data.  That's "expensive" but very do-able on a grid 
environment.

gerry
-- 
Gerry Creager -- gerry.creager at tamu.edu
Texas Mesonet -- AATLT, Texas A&M University
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