[Beowulf] 3d rendering cluster

[Robert G. Brown]

On Tue, 24 May 2005, Andrew Piskorski wrote:

> On Tue, May 24, 2005 at 02:48:31PM +0100, John Hearns wrote:
> 
> > Does this Windows software require direct access to the hardware?
> > If it works OK, you could use virtualization such as Zen on Linux nodes
> > to give you Windows machines for the sound application.
> 
> No, that won't work.  The Xen researchers did port Windows to run on
> top of Xen, but AFAIK Microsoft either refused outright to let them
> release it, or has not yet given permission.  So unless you already
> have a Windows XP source license (and maybe even then), you are
> definitely out of luck there.  (I am told Xen works very very well
> with Linux, though.)
> 
>   http://wiki.xensource.com/xenwiki/XenFaq#head-fcb85a149da66907086cc8ba4f0793ad01769b92
> 
> You probably could run this (unspecified) Windows app under VMware,
> but you'll probably take a significant performance hit.  (Try the
> latest VMware version 5, it is supposed to be faster.)  You might even
> be able to run it under Wine, which if it works at all would
> presumably be faster than VMware.

Or Cedega, which is basically Wine on steroids for gamers.  See
www.transgaming.com.  Or Win4Lin.  However these two (and vmware) cost
money -- quite a bit for vmware, less for win4lin, anything from none to
about the same for cedega (which is open source but requests that you
pay a subscription fee to help support its continued development).

I actually think that you need a windows license to run windows under
vmware as well -- it is just a shell for running virtual operating
systems, not a windows emulator.  The others, IIRC, are emulators, no
separate license needed.

Whether you need something beyond wine/cedega depends pretty strongly on
the software itself.  If it is a simple windows app, no fancy libraries
or forked windows applications (such as explorer) it is actually quite
likely that it will run, although a sound application MIGHT not have the
right device support if it does too much stuff raw and you have odd
sound cards.

Either way you have your work cut out for you.  A windows application
per node will be single threaded almost by definition, and will (of
course) use WINDOWS to run requiring a local graphics adapter and KVM.
So you'll have to equip the entire cluster with a KVM switch and do a
lot of very tedious switching between screens unless they've written the
application for a COMMAND LINE or so that it can be parallelized in some
way, both almost infinitely unlikely.

One thing I'd strongly recommend is that you look into the linux world
for an alternative.  What, exactly, are you trying to do with sound?
There are whole sound toolboxes for linux (see e.g. sox) that can read
in a sound file in nearly any format and convert it to nearly any other
format.  There are tools that permit you to hand-edit the actual
waveforms.  See here for a somewhat dated list of what's available:

  http://www.osnews.com/story.php?news_id=1511

Lots of these (e.g. audacity) are available prebuilt and yum-installable
for rpm-based distros e.g. FCX and have apt/deb packages available as
well.

Although these are often GUI tools as well, they run on top of X11 and
can run on a node and display on a remote console transparently.  If you
are into editing waveforms, at least one of them will likely provide you
what you need (and if not, as open source projects, you can work to GET
what you need into the tools with an immediate and obvious payback).  If
you are simply dealing with format conversion and/or waveform
transformation, sox is very likely your best friend.  It is a COMMAND
LINE tool and hence entirely suitable for being wrapped up into a script
and run across a cluster via e.g. SGE.

These tools will save you a ton of money on software if you can find one
that will work for you, and make the issue of windows (emulated or
otherwise) moot.  Many of them are likely to be either already installed
on any give linux workstation or a "yum install xxxx" away.  This is
just one of many, many things that give linux its incredible power.
Power users have been writing free power tools for it for a full decade,
and BEGAN with a set of power tools that had been written over the
decade before THAT, so you've got 20+ years of serious and high quality
free/GPL stuff to work with before you even LOOK for commercial
applications, which also exist where there is a market for them.

   rgb

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu