Posted by Fraser Campbell
Thu, 18 Jan 2007 04:33:00 GMT
linux.com yesterday published an interview with Jeff Dike (author/maintainer of UML). The linux.com interview is available at http://www.linux.com/article.pl?sid=07/01/16/2037250.
It sounds likely that UML will soon be ported to make use of hardware virtualization extensions. This support will be via the KVM kernel subsystem.
Many interesting twists to this story:
- Xen popularizes paravirtualization
- Xen doesn’t get mainline kernel port
- VMware gets on the bandwagon with VMI proposal
- finally paravirt support starts creeping into the kernel
- KVM jumps into the fray (out of the blue)
- KVM now uses paravirt support
- along comes the grand-daddy of Linux virtualization (UML) building on top of both KVM and paravirt
- still no Xen in mainline support
On a related note, Jeff made a very interesting presentation last summer at OLS. The paper was entitled “Linux as a Hypervisor” and can be downloaded as part of the 2006 OLS Proceedings Volume 1.
In this paper Jeff argues that the Linux kernel itself is a very capable virtualization manager. He points out that many of the “fancy” new features being added to the kernel in the past few years have had great benefits for virtualization (async and direct I/O primarily are mentioned).
Another interesting part of the paper was that he mentioned namespace virtualization patches (containers) and how they can be a boon to UML as well by allowing processes to make system calls directly on the host kernel.
One could definitely forsee that hypervisors might be irrelevant before too long. The linux kernel has most of the features that virtualization solutions need (NUMA, SMP, AIO, DIO, volume management, memory management, etc, etc, etc.) why duplicate all of code in a hypervisor as well – UML kernels as a very thin wrapper around the host kernel could yet become the sweetest deal of all.
Posted in User Mode Linux, KVM | no comments
Posted by Fraser Campbell
Thu, 18 Jan 2007 04:32:00 GMT
KVM is definitely generating some buzz these days. Soon it will be in the stock Linux kernel (2.6.20), it is gaining paravirtualization features and in general it seems like a nice, clean, simple solution.
Who would have predicted that the first user of the paravirt_ops kernel functionality is likely not to be Xen or even VMware, it will almost certainly be KVM (dozens of non-mainline patches excepted of course).
LWN posted an good article on these recent developments, author Jonathon Corbet states:
Perhaps the most interesting outcome of all this, however, is how KVM is gaining momentum as the virtualization approach of choice – at least for contemporary and future hardware. One can almost see the interest in Xen (for example) fading; KVM comes across as a much simpler, more maintainable way to support full and paravirtualization. The community seems to be converging on KVM as the low-level virtualization interface; commercial vendors of higher-level products will want to adapt to this interface if they want their products to be supported in the future.
Interesting indeed. LWN’s article includes a fair amount of technical details, it’s definitely worth a read over at http://lwn.net/Articles/216794/.
Posted in KVM | no comments
Posted by Fraser Campbell
Sat, 06 Jan 2007 18:35:00 GMT
Yesterday project ConVirt released version 0.6. I haven’t discussed this project before, here the introduction from their webpage:
Project ConVirt is an active, open source project concieved with the goal of tackling the administrative and infrastructure management challenges that adoption of virtualization platforms presents to the traditional datacenter. The XenMan administrative console is project ConVirt’s first release.
XenMan is an intuitive, graphical management tool aimed at operational lifecycle management for the Xen virtualization platform. XenMan is built on the firm design philosophy that ease-of-use and sophistication can, and should, co-exist in a single management tool. So, XenMan should hopefully prove valuable to both seasoned Xen Administrators as well as those just seeking an introduction to Xen Virtualization.
With XenMan’s secure, multi-node administration, performance management and provisioning capabilities, administrators can safely manage their entire environment from a single, centralized console. Most common administrative tasks like starting, stopping, monitoring and provisioning virtual machines (Guest OS’s) typically involve just a few mouse clicks with XenMan; as do server management operations like scanning OS configurations or acquiescing individual servers for maintainance.
For more details see ConVirt’s homepage.
Posted in ConVirt, Xen | no comments
Posted by Fraser Campbell
Sat, 06 Jan 2007 04:37:00 GMT
In a post to kvm-devel this afternoon, Ingo Molner announced a patch to support paravirtualization under KVM. The support speeds up context switches and TLB flushes.
The email announcement is here, some interesting snippits:
2-task context-switch performance (in microseconds,
lower is better):
native: 1.11
----------------------------------
Qemu: 61.18
KVM upstream: 53.01
KVM trunk: 6.36
KVM trunk+paravirt/cr3: 1.60
KVM will be available in the stock 2.6.20 kernel, great news and at the current pace I’d expect it to be quite a powerful solution before long.
Would be great to hear from Qumranet though …
Posted in KVM | no comments
Posted by Fraser Campbell
Sun, 31 Dec 2006 03:40:00 GMT
Recently one of my weekly computer rags had this to say:
A recent study at the University of New Hampshire found that 38 per cent of the U.S.’s power supply was being absorbed by data centres. According to IDC, businesses will need an additional 12 million square feet of data centre space by 2009.
While not entirely on the topic of linux virtualization it is one of the prime drivers behind the virtualization trend. 38% is an astounding figure, I can only hope it is not true.
The full article making this claim is available from http://www.itbusiness.ca/ in article IBM takes on HP, Sun with blade system.
Posted in Misc | no comments
Posted by Fraser Campbell
Sat, 30 Dec 2006 05:18:00 GMT
From the Xen development team …
We’re pleased to announce the official release of xen 3.0.4!
This is largely an opportunistic stabilising release for HVM guests, due to the large amount of work in that area of the code since 3.0.3. These enhancements have in particular improved support for SMP and ACPI Linux and Windows operating systems.
Other highlights of this release include:
- support for kexec/kdump of Xen and domain 0;
- graphical framebuffer support for paravirtualised guests;
- preview support for the new XenAPI management interfaces;
- enhanced support for IA64 (IPF) and Power systems.
Since 3.0.4 is an interim release, certain features such as HVM save/restore will now be part of Xen 3.0.5 which we expect to release in early 2007.
You can get the source using mercurial from:
http://xenbits.xensource.com/xen-3.0.4-testing.hg
Source and binary tarballs, and RPMs, will be made available from:
http://www.xensource.com/downloads
Posted in Xen | no comments
Posted by Fraser Campbell
Mon, 25 Dec 2006 00:20:00 GMT
From project homepage:
MLN (Manage Large Networks) is a virtual machine administration tool designed to build and run virtual machine networks based on Xen and User-Mode Linux. It is ideal for creating virtual network labs for education, testing, hosting or simply playing around with Linux.
The mln-help and mln-devel lists don’t look very busy but it could still be a useful tool. Take a look at
http://mln.sourceforge.net/index.php. I would be interested in hearing from anyone who has tried it out.
Posted in Xen, User Mode Linux | no comments
Posted by Fraser Campbell
Mon, 27 Nov 2006 02:28:00 GMT
Recently Avi Kivity posted to linux-kernel a patchset that adds save/resume support to KVM. See email at http://comments.gmane.org/gmane.linux.kernel/467458.
I have given KVM a run under Ubuntu and while it did work (I ran both CentOS 4 and Windows XP as guests) things were decidedly slow. One would assume that as development progresses on KVM this situation will improve.
KVM would certainly not appear to be the toy variety of virtualization like lhype. Simply considering the founders and backing of KVM one would assume that there is significant functionality and performance to be had from KVM down the road.
Qumranet (the company driving KVM) has as it’s founder Moshe Bar, Moshe is founder of the OpenMosix project and was one of the co-founders of XenSource. One would expect that very interesting things are on their way from this company …
Posted in Kernel, KVM | no comments
Posted by Fraser Campbell
Mon, 27 Nov 2006 02:08:00 GMT
In case anyone missed it (like myself) you may be interested in yet another hypervisor.
Rusty Russell is working on what he describes as “a trivial in-kernel hypervisor”. See email at http://lists.osdl.org/pipermail/virtualization/2006-November/001794.html.
This hypervisor is an in-kernel hypervisor and is meant as a demo for paravirt-ops – of course the Linux kernel started of as a toy project as well didn’t it?
Posted in Kernel | no comments
Posted by Fraser Campbell
Sat, 11 Nov 2006 15:57:00 GMT
The KVM project website is now up. For those interested in more details see the KVM Whitepaper.
One would wonder if hypervisors are losing their relevancy. With UML already in the kernel and KVM hopefully on the way the kernel already has the native ability to create a “virtual machine” (at least in some sense of the word). The argument against maintaining NUMA, SMP, multi-core support, etc. in both a hypervisor and the kernel makes a lot of sense to me.
KVM is now included in Andrew Morton’s -mm kernels, see announcement for 2.6.19-rc5-mm1.
Posted in Kernel, KVM | no comments
