An Overview of Virtualization Technologies

PCM2 writes "Virtualization is all the rage these days. All the major Linux players are getting into the game with support for Xen, while Sun has Solaris Containers, Microsoft has Virtual PC, and VMware arguably leads the whole market with its high end tools. Even AMD and Intel are jumping onto the bandwagon. InfoWorld is running a special report on virtualization that gives an overview of all these options and more. Is it just a trend, or will server virtualization be the way to go in the near future?"

Comments

Of course it's a trend

[Flying pig]

Yesterday's mainframe, today's rackmount server, tomorrow's desktop. As computers get faster, software functions at ever higher levels of abstraction. The holy grail is when you have the array of blade servers which you can grow or shrink on the fly, the sea of running operating systems, and the application that spreads itself across the lowest loaded operating systems as needed. Fault tolerance, load balancing, all out of the box.

With the growing evidence of the human brain's ability to rewire itself and route around failures on the fly, and the effective virtualisation of perception (why do I appear to see a three dimensional picture of the world when I have only 2 curved arrays of photosensors?) we are probably just following a well trodden evolutionary path.

And IBM? Where are they?

[ptitvert]

What kind of article is that?

They talk about VMWare, Intel/AMD, the future Solaris on E10000, other things... but where is IBM?
They can do Virtualization for at least 3 years with their Regatta technology (P670, P690 (Power 4 technology), P530, P550, P560, P570, P575, P590, P595 (Power 5 technology)) and their OS AIX 5L.

they are able to give a few percentage of a cpu to virtual server, with their Virtual IO server, they also are able to virtualize network and disks. They can do workload management between virtual servers. Add/remove disks/cpu/memory in real time.

etc...

So for a complete discussion an overview of the virtualization in the industry, IBM is now a big player, and they are now surpassing SOLARIS & HP in the "closed" unix world.

So for me this overview is not complete and should not have passed the "draft" version until someone was looking at the actual and running alternatives.

L.G.

Re:Just a trend? NO WAY

[interiot]

Not a huge percentage of people dual-boot. But hopefully virtualization will increase the ease of use of Linux and ALL other alternative operating system as well. There are hundreds of home-grown OS's out there, and it would be cool if virtualization were easy enough to use that people just download and run it to test it out, making OS's as easy to try out as applications.

We need to ask M/s Microsoft, Intel, AMD, Sun etc.

[jkrise]

Virtualisation is a disruptive technology... in that it requires a lot of intellectual investment on the part of the sysadmin. The reason Unix and Windows Servers have gotten by without adding much features, yet retaining market share is simple... admin lethargy and apathy.

Microsoft does not seem to like virtualisation.. hell, they didn't like Terminal Services.. so they crippled it in NT4, made extra licensing restrictions with Win2K, and made the WinXP / Metaframe XP combn. a non-starter. In microsoft's world, users must only license MS's servers and everything needs a separate server /client.

Now that the virtualisation market has grown IN SPITE OF the apathy of these s/w vendors... and the tremendous mindshare with Open Source technologies, these old chaps are trying to make money without doing anything themselves.. witness the recent MS licenmsing options in virtual segments, acquisition of IP, Intel's hypervisor efforts, AMDs efforts etc.

If virtualisation succeeds, it could spell the end for DRM and Treacherous Computing initiatives... since these need collective collusion by all parties involved. Looks like the firms mentioned will try their damnedest to sidetrack virtualisation.. just like terminal servics and thin clients never reached their full potential. Open Source firms and nerdy sysadmins might well have the last laugh...

Re:Just a trend? NO WAY

[jeswin]

Well, the fact is the virtualization is a work-around poorly written and designed OSes and applications. Virtualization is succeeding because we cannot build OSes that: 1. Prevent applications from littering and destroying public space 2. Do a decent migration without re-installs 3. Can scale without re-installing and re-configuration 4. Do better throttling and pooling And we cannot build applications that: 1. Know how to co-operate with other applications, atleast be aware that the system cannot be monopolized. 2. Install in a private space Some time back I had written a blog about Virtualization, isn't it a Diversion? Summary: Virtualization looks like necessary evil, because we are incompetent to write better OSes and Application. Virtualization is the easier route. And, you wait till it reaches critical mass, gets everywhere and brings its share of problems. I would have preferred a better, from the ground-up OS any day. Hurd, or ever better Singularity!

Where is the real info?

[IDontLinkMondays]

Well, first of all, I'd like to point out that I've run on virtualized systems for the entire extent of my career. Not specifically in the sense which we run now, but in the sense that back in the old days, we ran IBM mainfraim operating systems on IBM systems that actually were virtual machines. They included features such as segmentation and all the good stuff which is just coming around now.

Thanks to other technologies I've run similar systems for ages. It is entirely common for me to develop a file system driver while keeping Mac OS X, Windows, Linux, and DOS running on the same system. I've done this for a long time as well. The difference is that the operating systems would be virtualized by running system emulators instead of using CPU technologies for system segmentation. I did this in the old days under DOS using Quartdeck Desqview and a CPU emulator.

First thing that people really need to understand at this point that virtualization as we're using it today is little more than finding a method to lauch operating systems as "processes" under another operating system. This is not magic, for the most part it's something that any operating system developer should be capable of. The issue is more of grinding. It takes the right kind of people to sit and grind through each of the problems that come up with running like this. It's the same idea as writing a Windows compatible API stack. You start off with simple programs you have the source for and work your way up through more complex applications that require direct hardware access. It's a matter of intercepting the calls and handling them as if you were the real thing.

So here's the deal. As a system level developer, I am more interested in what these guys are actually doing in order to make it happen. Let's face it, although Intel and AMD are adding virtualization technologies to their processors, the actual task of switching between CPU contexts is hardly an issue. The real issue is how are they handling hardware emulation.

See, to me, I focus on high performance workstation related tasks. Servers are cool and great, but in reality, it's how it performs on the desktop that is truly important to me. What I want to see is that a vendor grinds a little more on this issue.

VMWare has classically written device drivers to handle hardware interfacing with better performance than others. So instead of simply emulating the VESA BIOS extensions and providing access to an SDL style frame buffer, instead they have written drivers to allow graphics acceleration. So what I really want to see is that they take it a step further....

I want more than just accelerated BitBlt functions. Of course in the 2D desktop world, high performance frame buffer moves are not optional but required since the bus bandwidth required to copy large frame buffers all around is outrageous. But in the days where OS X uses OpenGL and Windows Vista uses DirectX, I want drivers that interpret 3D contexts as well.

So here's what I'm thinking... write a 3D driver for Windows, Mac OS X, X. The driver should of course offer frame buffer handling, but this shouldn't be the focus since it isn't used for much more than boot and text mode processing. When an OpenGL context is created, instead of creating the context native to the virtual machine, the context should occur on the host operating system and should be managed there. The only interprettation should occur when the graphics driver informs the guest operating system of the top level context.

For direct X, well, I've seen at least one virtual driver in the past which implemented Direct X on Open GL. For professional graphics, Direct X is typically seen as a toy although in reality in many ways it's more powerful than OpenGL (don't argue, it has to do with what's more important to hardware vendors so their drivers are optimized for game based testing). So, since most professional graphics packages are OpenGL based, then the virtualization software vendor should simply implement a translation layer ov