An Introduction to Virtualization

JamieX writes "kernelthread.com brings you a very cool and instructional article in An Introduction to Virtualization... The piece talks about the history of VM's, why they are becoming important again, implementation issues and most of all a look at a large number of virtualization solutions for all kinds of operating systems... many of them barely known... essentially more than you want to know about virtualization on a single page! Great read and reference."

Comments

vmWare's ESX server uses Linux Kernel?

[stonebeat.org]

I thought vmWare's ESX Server used a Linux Kernel. Or is it just the installer that is based on Linux.

Re:vmWare's ESX server uses Linux Kernel?

[stonebeat.org]

ok I think I answered my own question. Here is what vmware says:
"VMware's patented and patent-pending technology serves as the foundation for VMware ESX Server; it is not derived from Linux or FreeBSD." @ VMware ESX Server 2 FAQs

Linux is only used a bootloader, and for I/O to the console on the ESX Server.

Lack of comments.

[lynx_user_abroad]

I take it from the lack of comments that most of the slashdot crowd is unfamiliar with this stuff.

There are certain advantages to having cut ones teeth on the IBM mainframe.

Heads-up, people. This stuff is way cool. Think of it like a MATRIX you own.

Re:Lack of comments.

[Slashamatic]

ABout the limit for many people here is vmware to run Windows under Linux (or vice versa), and UML because it is used by many hosting providers.

The problem comes down to the sucky IA-32 architecture which is hard to virtualize. Take a privileged mode instruction on a proper architecture, and it will trap allowing it to be emulated. Some IA-32 instructions do not trap but return different mode-dependent results. A nightmare.

For me what is interesting are domains, giving a very fine level of VMs to CPU allocation. A CPU may be reserved for a single VM or be shared by many, in turn many CPUs can be devoted to a single VM This gives very fine resource control and is what you get now on heavy iron such as the IBM Z-series or the big Sun machines.

This is why I follow the Xen project with some interest. Xen needs mods to the host OS to get around the shortcomings of the IA-32, but they are minor and well defined (replacement of some macros). It isn't there now, but maybe if they get enough people working on it, it could be very interesting indeed.

The article omits XEN & coLinux

[vinsci]

Oddly enough the article doesn't even mention XEN, one of the most interesting virtualization systems. Xen is being actively developed and has also been featured on Slashdot a couple of months back when they released the first public versions.

Also omitted is the new coLinux, which was discussed on Slashdot, too, just the other week.

Wow! New technology from 1967

[Dark$ide]

IBM have been doing this on s/360 since CP/67.
It's hardly new and I can't see how VMWare can get a patent, it's prior art.