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Xen High-Performance x86 Virtualization Released
The Xen team continues: "Xen requires guest operating systems to be ported to run over it. Crucially, only the kernel needs to be ported, and all user-level application binaries and libraries can run unmodified. We have a fully functional port of Linux 2.4.22 running over Xen, and regularly use it for running demanding applications like Apache, PostgreSQL and Mozilla. Any Linux distribution should run unmodified over the ported kernel. With assistance from Microsoft Research, we have a port of Windows XP to Xen nearly complete, and are planning a FreeBSD 4.8 port in the near future.
"Visit the project homepage to find out more, and download the project source code or the XenDemoCD, a bootable 'live iso' image that enables you to play with Xen/Linux 2.4 without needing to install it on your hard drive. The CD also contains full source code, build tools, and benchmarks. Our SOSP paper gives an overview of the design of Xen, and evaluates the performance against other virtualization techniques.
"Work on Xen is supported by UK EPSRC grant GR/S01894, Intel Research Cambridge, and Microsoft Research Cambridge via an Embedded XP IFP award."
> Xen requires guest operating systems to be ported to run over it.
Get me all excited, then pull the rug out from under my why don't you? This is still pretty neat, but it's hardly a replacement for VMWare or Bochs.
Javascript + Nintendo DSi = DSiCade
From the page (which hasn't bet /.'ed... yet)" you can read that Xen itself is GPLed:
"Modern computers are sufficiently powerful to use virtualization to present the illusion of many smaller virtual machines (VMs), each running a separate operating system instance. Successful partitioning of a machine to support the concurrent execution of multiple operating systems poses several challenges. Firstly, virtual machines must be isolated from one another: it is not acceptable for the execution of one to adversely affect the performance of another. This is particularly true when virtual machines are owned by mutually untrusting users. Secondly, it is necessary to support a variety of different operating systems to accommodate the heterogeneity of popular applications. Thirdly, the performance overhead introduced by virtualization should be small.
Xen is a virtual machine monitor for x86 that supports execution of multiple guest operating systems with unprecedented levels of performance and resource isolation. Xen is Open Source software, released under the terms of the GNU General Public License. We have a fully functional port of Linux 2.4 running over Xen, and regularly use it for running demanding applications like MySQL, Apache and PostgreSQL. Any Linux distribution should run unmodified over the ported OS.
With assistance from Microsoft Research, we have a port of Windows XP to Xen nearly complete, and are planning a FreeBSD 4.8 port in the near future (volunteers welcome!). "
If you had botherd to open the Xen link,
and read the page which was a whopping
8100 bytes in size you would of noticed
"Xen is Open Source software, released under the terms of the GNU General Public License. We have a fully functional port of Linux 2.4 running over Xen, and regularly use it for running demanding applications like MySQL, Apache and PostgreSQL. Any Linux distribution should run unmodified over the ported OS."
rather then just trolling off the two words "Microsoft Research"
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Which Helpless Linux zealot/MS basher do you want to mod down today?
Virtualization rocks for that kind of things. I happily use FreeBSD jails for that. They work on a different level and have different goals, but giving each (group of) user(s) their own sandbox to play with is definitly a really cool thing, both for admins and for the users themselves.
Programming can be fun again. Film at 11.
So it looks like this is the third (or fourth) free VM for Linux, the others being Plex86 (and a different fork here) and User Mode Linux. Does anyone have a good comparison of these three? I know Zen compared UML on their site but not plex86. I'm not really sure of the differences between them, particularly the different versions of plex86 and UML (Zen explained their virtualization process pretty well on their site). Which is the best choice for different scenarios? It looks like Zen is the winner for running Linux as the guest OS, and the original Plex86 (first link) is the only one which offers a free choice in guest OS's.
When you lose something irreplaceable, you don't mourn for the thing you lost, you mourn for yourself. - Harpo Marx
This is Cambridge computer lab we're talking about - where Microsoft research have the very next building over.
I live with one of the guys in the systems group and hope to go back there to do my PhD soon, and they do do very cool things there. Microsoft give them all the help they need, because academia is an excellent ideas feeder for the real world. Cambridge, being in a position of power with its serious reputation and fantastic set of minds, gets the benefit of the Microsoft help without any of the assumed costs.
Henry
i don't do sigs. oops.
According to the README, it requires special hardware drivers and is not targetted at desktops. Don't expect stellar graphics performance. VMWare *does* give you something for the money.
Hardware support
================
Xen is intended to be run on server-class machines, and the current
list of supported hardware very much reflects this, avoiding the need
for us to write drivers for "legacy" hardware. It is likely that some
desktop chipsets will fail to work properly with the default Xen
configuration: specifying 'noacpi' or 'ignorebiostables' when booting
Xen may help in these cases.
Xen requires a "P6" or newer processor (e.g. Pentium Pro, Celeron,
Pentium II, Pentium III, Pentium IV, Xeon, AMD Athlon, AMD Duron).
Multiprocessor machines are supported, and we also have basic support
for HyperThreading (SMT), although this remains a topic for ongoing
research. We're also looking at an AMD x86_64 port (though it should
run on Opterons in 32-bit mode just fine).
Xen can currently use up to 4GB of memory. It's possible for x86
machines to address more than that (64GB), but it requires using a
different page table format (3-level rather than 2-level) that we
currently don't support. Adding 3-level PAE support wouldn't be
difficult, but we'd also need to add support to all the guest
OSs. Volunteers welcome!
We currently support a relatively modern set of network cards: Intel
e1000, Broadcom BCM 57xx (tg3), 3COM 3c905 (3c59x). Adding support for
other NICs that support hardware DMA scatter/gather from half-word
aligned addresses is relatively straightforward, by porting the
equivalent Linux driver. Drivers for a number of other older cards
have recently been added [pcnet32, e100, tulip], but these are not
recommended since they require extra packet copies.
in case anyone forgot, not only is microsoft research their neighbor, but it was also the first microsoft research center outside the us. wired has more about what you can get for $80 million.
...vividly encapsulates that post-Watergate/pre-punk/coked-up moment when you could trust no one, least of all yourself.
http://www.opersys.com/adeos/index.htmla vannah.nongnu.org/projects/adeos
http://s
"The purpose of Adeos is to provide a flexible environment for sharing hardware resources among multiple operating systems, or among multiple instances of a single OS."
This is similiar to xen and the new plex86 and it has some experience with supporting rtos
from the ADEOS site (http://www.nongnu.org/adeos/):
"The Adeos Project
The purpose of Adeos is to provide a flexible environment for sharing hardware resources among multiple operating systems, or among multiple instances of a single OS.
To this end, Adeos enables multiple prioritized domains to exist simultaneously on the same hardware. For instance, we have successfully inserted the Adeos nanokernel beneath the Linux kernel, opening a full range of new possibilities, notably in the fields of SMP clustering, patchless kernel debugging and real-time systems for GNU/Linux."
this thing is used in the RTAI realtime linux project.
We did benchmark against VMWare 4 (and ESX), but those versions have a clause in their licence agreements forbidding publishing of benchmarking results without VMWare's permission. They refused us permission, from which you can deduce who is faster. =)
Torne
(XenoXP porter)