Ian Pratt announced the official release of Xen 2.0, "the open-source Virtual Machine Monitor." The project's FAQ explains, "Xen can securely execute multiple virtual machines, each running its own OS, on a single physical system with close-to-native performance." Their performance page offers some comparisons of Xen to native Linux, as well as to two other virtualization projects, VMware and User-Mode Linux [story]. Xen will currently run both the 2.4 Linux kernel [forum] and the 2.6 Linux kernel [forum], as well as NetBSD [forum]. Support for running FreeBSD and Plan9 is scheduled to be added within the next few weeks. Ian explains in his release announcement:
"Xen 2.0 runs on almost the entire set of modern x86 hardware supported by Linux, and is easy to 'drop-in' to an existing Linux installation. The new release has a lot more flexibility in how guest OS virtual I/O devices are configured. For example, you can configure arbitrary firewalling, bridging and routing of guest virtual network interfaces, and use copy-on-write LVM volumes or loopback files for storing guest OS disk images. Another new feature is 'live migration', which allows running OS images to be moved between nodes in a cluster without having to stop them. Visit the Xen homepage for downloads and documentation."
From: Ian Pratt [email blocked] To: linux-kernel Subject: Xen 2.0 Officially Released! Date: Fri, 05 Nov 2004 14:17:43 +0000 The Xen team are pleased to announce the release of Xen 2.0, the open-source Virtual Machine Monitor. Xen enables you to run multiple operating systems images concurrently on the same hardware, securely partitioning the resources of the machine between them. Xen uses a technique called 'para-virtualization' to achieve very low performance overhead -- typically just a few percent relative to native. This new release provides kernel support for Linux 2.4.27/2.6.9 and NetBSD, with FreeBSD and Plan9 to follow in the next few weeks. Xen 2.0 runs on almost the entire set of modern x86 hardware supported by Linux, and is easy to 'drop-in' to an existing Linux installation. The new release has a lot more flexibility in how guest OS virtual I/O devices are configured. For example, you can configure arbitrary firewalling, bridging and routing of guest virtual network interfaces, and use copy-on-write LVM volumes or loopback files for storing guest OS disk images. Another new feature is 'live migration', which allows running OS images to be moved between nodes in a cluster without having to stop them. Visit the Xen homepage for downloads and documentation. http://xen.sf.net
From: Jeff Garzik [email blocked] Subject: Re: Xen 2.0 Officially Released! Date: Fri, 05 Nov 2004 12:08:20 -0500 Ian Pratt wrote: > The Xen team are pleased to announce the release of Xen 2.0, the > open-source Virtual Machine Monitor. Xen enables you to run > multiple operating systems images concurrently on the same > hardware, securely partitioning the resources of the machine > between them. Xen uses a technique called 'para-virtualization' > to achieve very low performance overhead -- typically just a few > percent relative to native. This new release provides kernel > support for Linux 2.4.27/2.6.9 and NetBSD, with FreeBSD and Plan9 > to follow in the next few weeks. Xen is pretty darn neat -- any plans to merge into upstream Linux kernel? Jeff
Windows support
Xen is really useful.
It'd be nice if Microsoft allowed the distribution of the Windows port/Windows version!
Useful as tits on a bull
The primary non-server use for virtualization software is to run untrustable (proprietary) operating systems on a trusted F/OSS platform. Xen can not do this. It's pretty ironic that as of today the only way to do that is with proprietary virtualization software.
> The primary non-server use
> The primary non-server use for virtualization software is to run
> untrustable (proprietary) operating systems on a trusted F/OSS
> platform.
Although it's also useful for other applications, Xen is explicitly aimed at server space. The feature set has always been targeted at this market and it's well equipped to exist in that space. Since Xen runs a several popular server OSs and supports live migration, resource accounting, etc, it's well placed to compete with the likes of VMWare's server products. Running Windows apps on Linux isn't the problem it's trying to solve.
> It's pretty ironic that as of today the only way to do that is with
> proprietary virtualization software.
You can run Windows et al under QEmu, although it's not as fast as VMWare (yet - this is being worked on). QEmu is a work in progress but it is already very impressive.
huh?
qemu is not a virtualizer, it is an emulator. There is a huge difference between the two concepts with respect to performance and difficulty of implementation.
It depends on the definitions
It depends on the definitions you use. I like to think of QEmu, Bochs et al as being special cases of virtualisation where *everything* is run by a software interpreter, rather than bare metal. In VMWare, some stuff is simulated in software, while other stuff runs on bare metal. In Xen, everything sees bare metal.
But yes, QEmu does it's work in a very different way to VMWare and Xen. Fabrice is planning to add support for a VMWare-style mode.
Yet another step towards trustable linux services
Virtualised Linux Standard Base (VLSB)
in Virtual Demilitarized Network Zones (VDNZ)
from Trusted Build Agents (TBA).
Twelve Step TrustABLE IT.
IMHO, WTF? BFN, TTYL.
IMHO, WTF?
BFN, TTYL.
sysemu patch
I wonder which version of skas they are running; in particular, does it contain the sysemu patch?
You mean in the benchmarks?
Do you mean for the benchmarks?
IIRC, the UML benchmarks included a whole load of tweaks to make UML perform well. I don't know what exactly they were, although there's a post on the Xen mailing list about it. I don't really follow UML development but I suppose there may have been some more enhancements since then. I'd still expect Xen to perform better, though.
Benchmark against linux-vserver?
I think it would be a lot more interresting to see a benchmark against linux-vserver because that also has a very low overhead(yes I know it is only for linux)
I'd imagine the benchmark res
I'd imagine the benchmark results for Vservers would be basically the same as for native Linux.
VServers is also pretty cool stuff and for some deployments will be the best choice (depending on requirements). I was very impressed when I tried it.
sysemu patch
You're confusing User Mode Linux with Xen here ;-). Skas is related to UML only (http://user-mode-linux.sourceforge.net/skas.html).
No confusion here
The benchmark page compares UML with Xen.
Did anybody try this yet?
I wonder if anybody here tried xen already - I just don't have any space available at the moment ('full' is the perpetual state of harddisks). It looks very interesting.
I hope it will boost the virtual machine hosting market. Most people just don't need a big machine to have their own little domain running with some email and web pages... Well, I don't, and I don't like the idea of having a rather expensive machine in a rather expensive hosting facility standing there in mostly idle state. And once you're used to having root on any machine and tuning operating systems to your liking, you don't really want to have a shared server account.
Hmmm... Upcoming FreeBSD support, is that for host OS, guest OS, or both?
FreeBSD
Definitely guest OS, not sure about host OS...
Xen is the host OS
Sorry, sure of what you say? IIRC, actually Xen is the host OS, and then Linux is a guest of it. Much like what happens on S/390, only difference is that on S/390 it's not possible to run Linux as host OS, while anywhere else it's the most common or the only alternative.
True - it's a fair cop, gov ;
True - it's a fair cop, gov ;-) I was playing fast and loose with the terminology when I posted my reply! Xen is really the host for all OSs running on top of it, like the S390 VMM or VMWare ESX server. OSs in virtual machines are always guests of Xen.
Xen 2.0 doesn't contain management software or device drivers, unlike the VMWare product (and the s390 VMM, I suspect). There is a distinction between an OS which is capable of running in an unprivileged virtual machine and an OS which can also run the device drivers and management plane software.
When I said I wasn't sure if FreeBSD could run as a host, I *really* meant that I wasn't sure if it could run the device drivers + management software ("domain 0 functionality" in Xen terminology). This doesn't really make it the host, it just looks like it from the user's PoV.
FreeBSD support
Guest OS support for FreeBSD already exists - the documentation is
pretty minimal but there is some:
http://www.fsmware.com/xenofreebsd/
Domain 0 support is likely further off. There have been a little over 100 hits, but no one has reported on his experiences - so I don't know how much demand for it there is out there.
What about OpenBSD?
OpenBSD firewalling support as a virtualized front end to a virtualized cluster would rock. ;-)
Jacob Mathai The xen 3.0
Jacob Mathai
The xen 3.0 release is, in fact, much better than 2.0. It offers better SMP support, a new scheduler, and a host of additional features.
http://xensource.com/xen/downloads/index.html