Beowulf & VMWare

Laurence laurenceliew at
Fri Nov 1 15:33:05 PST 2002


So what you are saying is that Scyld+Vmware is a
usable server consolidation platform of sorts... this
is interesting. 

Typically we see customers installing Vmware on a
server say a 4-way server, and put say 8 guest OS on
it. He is happy and let's it run "forever". He may
then go on to consolidate other servers with another
say TWO 4ways servers with Vmware.

Enter Scyld. You put the three 4-ways togather as a
Scyld cluster. Install all the guest OS on one. And
then let Scyld handle the allocation and migration of
the VMs. Is this what you mean?

This is interesting because one of the issues with
Vmware server consolidation is high availability. If
one server physically crashes, then the user will lose
all his Vms instances... so now with Scyld's method,
the VMs can be migrated "on-the-fly" to a backup or
other "free" machines.

Can Scyld released more information on such a

Laurence Liew

 --- Donald Becker <becker at> wrote: > On Fri,
1 Nov 2002, Laurence Liew wrote:
> > Vmware GSX/ESX is great for server consolidation.
> But consolidated 
> > servers are not meant for Beowulf clusters and
> vis-versa.
> Oh, I strongly disagree.  The Scyld system is being
> used for server
> consolitation.
> > Imagine your Oracle database processing a large
> transaction, and all of 
> > a sudden you start up a vmware session to do some
> other stuff... both 
> > your Oracle db and new vmware session will be
> severly impacted.
> That's why it's important to make both status
> monitoring and explicit
> node allocation part of the cluster system.  Status
> monitoring allows
> CPU loads and memory pressure to influence
> scheduling.  Explicit node
> allocation is an override to the automatic
> scheduling.
> > Server consolidation requires careful studies into
> loads of various 
> > applications that will be running on the server...
> you cannot just move 
> > the VMs around (I am thinking of openmosix +
> vmware.. dynamic vmware 
> > allocation in a cluster)...
> As most list readers know, I consider Mosix to be an
> academically
> interesting system and its transparent process
> migration an excellent
> touchstone to compare process migration approachs.
> Mosix is not a good system for scalable or
> performance-oriented
> clustering, and I agree with your conclustion that
> Mosix+VMware
> application serving is not a good match.
> > we see customers consolidating 100+ servers into 8
> - 10 large 4/8 ways 
> > servers. And in these 8-10 large servers.. Vmware
> sessions are carefully 
> > partitioned according to CPU loads, memory / disk
> space requirements.
> Specifically, you almost never want to migrate an
> already running
> VMWare instance.  Consider it something to be
> scheduled around instead
> of something to schedule.  This approach does work
> reasonably well for
> most server consolidation environments.
> -- 
> Donald Becker				becker at
> Scyld Computing Corporation
> 410 Severn Ave. Suite 210		Scyld Beowulf cluster
> system
> Annapolis MD 21403			410-990-9993
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