Linode KVM (beta)

Linode started in 2003 with User Mode Linux as the virtualization technology. We switched to Xen in 2008. Now, the time of KVM is upon us! We've integrated KVM into our platform and we'd love your help testing. Why KVM? Read on…

What is KVM?

Kernel-based Virtual Machine (KVM) is a Linux feature that exposes CPU VT virtualization extensions (among other things), thereby turning Linux into the hypervisor. Enabling KVM in the Linux kernel does nothing on its own – it simply creates a /dev/kvm device node which userspace software can use to take advantage of KVM. In the Linux KVM world, that userspace tool is QEMU. QEMU is the virtualization container, which can run guests at near native speeds when using KVM.

What does this mean for Linodes?

* KVM has less overhead, and therefore Linodes will run much faster. We found that on a Linode 4G, a KVM Linode compiles a kernel 27% faster than a Xen Linode.

Linodes can now boot direct-from-disk, using your Master Boot Record (MBR) and your bootloader, and your distribution's/OS's kernel.

Linodes can be either 32 (or 64) bit, without any exceptions, tickets or special requests.

Linodes can now run any operating system, as we now support full virtualization, in addition to para-virtualization. This means you can run all sorts of operating systems - from BSD to Plan9.

What are the guest differences?

The "Distro Helper" fixes these up for you on boot, depending on the hypervisor your Linode is booting under. So, you shouldn't need to worry about this – but, you'll need this info if you're running non-Linux OSs: KVM Linodes use /dev/ttyS0 for console and /dev/sd* for block device nodes. Xen uses /dev/hvc0 and /dev/xvd*, respectively.

Are there any beta limitations?

* The Linode KVM beta is now in all DCs except for Tokyo.

There is no graphical console, yet.

How does the beta work?

* We'll move one of your existing Linodes to one of these special hosts

There are limited slots available

This is experimental

You might lose all of your data

Participate at your own risk

This may be the LAST time you see that Linode

You really should have backups

Expect the unexpected

It is likely that you will experience downtime

This may cut you

No pain, no gain

What do I do as a beta participant?

First, please do make sure you have backups of your system. There are no guarantees how stable this thing will be. Secondly, you don't need to do anything special. We want to get a good sense of how this will perform under real-world workloads. Thirdly, if you want, feel free to perform some benchmarking on your own, and share your experiences here.

We'd also like to see what weird OSs you guys can get running.

Is the beta currently open?

Yes! - Click here to apply and we'll move the Linode you specify over to the KVM beta.

If you find a bug, or an issue, we'd appreciate it if you start a new forum thread instead of replying to this one.

-Chris