[221] in athena10
Re: Cluster machine reset idea
daemon@ATHENA.MIT.EDU (Greg Hudson)
Thu May 29 00:31:37 2008
From: Greg Hudson <ghudson@MIT.EDU>
To: Kenneth Arnold <kcarnold@mit.edu>
Cc: athena10@mit.edu
In-Reply-To: <483E2EC8.4040405@mit.edu>
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Date: Thu, 29 May 2008 00:30:52 -0400
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I think Sun machines may be going away this summer, but I don't think
the decision is finalized.
I am concerned about performance running user logins inside a VM,
particularly for graphically intensive course software. I'm also
concerned about the ability to clone login VMs fast enough to provide a
good serial reusability interface.
I am concerned about brokenness running user logins inside a
chroot--things like being able to contact the system dbus daemon.
Either of these sets of concerns may turn out to be manageable, but I'm
not sure if the resources to investigate them can come from IPS (my
group) given our workload. I can certainly see the advantages of one or
the other approach if they turn out to be viable.
On Thu, 2008-05-29 at 00:19 -0400, Kenneth Arnold wrote:
> About hardware-assisted virtualization: VirtualBox doesn't use it
> because it doesn't really speed things up for them. So maybe its lack
> isn't a big deal. As long as it's Intel on Intel.
>
>
> Matthew S Goldstein wrote:
> > However, instead of running the VMs locally, have the VM running on
> > servers elsewhere. The cluster machines will have a client which
> > connects to the VM, giving instant login. Once the client is
> > connected, a live migration starts of the VM to the cluster machine so
> > any extended login can take advantage of the local processing power.
>
> Maybe I'm just dull, but I don't see the advantage of that scheme over
> having the VMs always local (with central administration).
>
> It occurs to me that virtualization is just a better way to go in
> cluster management all around. It just enables so many things that
> weren't possible before. e.g., click a button and your session transfers
> to sipb-xen and keeps running while you go to class, you connect to it
> on your laptop during lecture, then go to another cluster and bring it
> up there. Or Athena 10 breaks some esoteric software... no problem, just
> pull up the Athena 9 image and run it there. Trivial software testing
> and upgrades. No more separate Windows and Linux machines either; run
> anything on any of them, at the same time even. (Too bad a VM can't
> grow/shrink memory usage on demand. Or can it? I noticed some things
> about memory hotplug in the Linux kernel...)
>
> Oh... what about all those Sun machines?
>
> -Ken
>
