topic Re: Virtual machine spanning multiple computers in VMware Workstation Pro Discussions

Virtual machine spanning multiple computers

martinhruska — Wed, 13 Oct 2010 09:50:33 GMT

Is it possible to create virtual machine spanning multiple computers? I have very processing power intensive program and I would like to run it "in the cloud" with power limited only by number of connected machines.

Is it possible or is it just nonsense.

Re: Virtual machine spanning multiple computers

AWo — Wed, 13 Oct 2010 10:24:03 GMT

Welcome to the forums!

In the year 2010 this must still be managed by the application (distributed processing where chunks of work are distributed and the results are put together again, like SETI). An OS is not capable to do this, even with virtualization. So the answer is: no. You can run a single OS only on a single computer. A virtual machine still needs to run on a single host, even in a cloud.

BTW, VMware Workstation is not a cloud-aware hypervisor.

AWo

VCP 3 & 4

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Re: Virtual machine spanning multiple computers

Noel — Wed, 13 Oct 2010 18:36:39 GMT

Welcome to the forums!
In the year 2010 this must still be managed by the application (distributed processing where chunks of work are distributed and the results are put together again, like SETI). An OS is not capable to do this, even with virtualization.

Well, actually, 20 years ago Groupe Bull had an OS that did precisely that. It allowed a single OS image to span entire networks and use resources as if it were a single computer. But I agree that no mainstream OS provides the functionality.

Re: Virtual machine spanning multiple computers

martinhruska — Wed, 13 Oct 2010 18:56:10 GMT

I remember that back at school we used Unix based thing called Mosix. It allowed whole network cluster to become "one computer" and automatically migrated processes to nodes with low load.

So I though, fifteen years later, with all the "cloud" buzz, it would be possible to have virtualization layer which could hide details and let Windows think that there is one big multicore computer.

But it seems I was wrong. Event Mosix isn't open source any more!

and there are people who had same idea as me: http://arstechnica.com/civis/viewtopic.php?f=16&t=710361

Re: Virtual machine spanning multiple computers

asatoran — Wed, 13 Oct 2010 23:33:25 GMT

...I have very processing power intensive program...

One of the "features" of virtualization is to be able to run multiple virtual machines on one host because each guest does not use all the processing power of the CPU. So maximizing utilization of an underutilized host. But you have just one OS that needs more power than just one host CPU. Virtualization tries to fit a bunch of "small" OS' onto one host. You're trying to fit just one really big OS onto multiple hosts because it won't fit on just one. So this, to me, is quite the opposite of what one would normally do with virtualization.

...with power limited only by number of connected machines.

Another feature of virtualization is to decouple the OS from the physical hardware. The virtual machine becomes "portable" so hardware failures are not as traumatic. But in your case, a failure of a "host" is not traumatic since the OS would load-shift to the other functioning machines. (e.g.: grid or cluster computing.) So the need for hardware decoupling is almost non-existent for your needs.

You really won't be using the features of virtualiztion, thus virtualization is not a solution for you.

Re: Virtual machine spanning multiple computers

asatoran — Thu, 14 Oct 2010 00:11:42 GMT

So I though, fifteen years later, with all the "cloud" buzz, it would be possible to have virtualization layer which could hide details and let Windows think that there is one big multicore computer.

Microsoft does have something that uses multiple machines and sort of hides the details: Microsoft Clustering Services (MSCS.) What you want is to make a "generic OS" become cluster-capable. One can imagine it would be possible but it wouldn't really be virtualization since virtualization doesn't hide the physical CPU. For example, when you lose a machine, how will generic Windows deal with going from 100 CPUs to 99? Thus you'll have do do something like emulate "just one CPU" to hide the change in CPUs. And emulation is not virtualization.

I'm not saying it's impossible. just that it's a technology that not really virtualization as it's done now. "Clouds" hide the details, but clouds don't have to be virtual either.

Re: Virtual machine spanning multiple computers

martinhruska — Thu, 14 Oct 2010 11:55:46 GMT

Ok, thanks. You have a point.

It seems that recommended solution is:

buy one big super multi socket multi core powerful computer
OR use application which can cooperate over network with it's instances on other nodes
OR use special cluster aware operating system