Here at Bitcube we use KVM as our preferred virtualisation platform. It has the best Linux support and is the standard for all Linux distributions. Whilst it still shows a bit of immaturity at times, there is an upside - rapid development and improvements.

Virtualisation has gone through four main phases:

• full software emulation - every instruction is emulated - very, very slow. (Bochs)
• software virtualisation - instructions are checked but most run natively. (VMWare server)
• paravirtualisation - the guest operating systems know they are virtualised and are tweaked appropriately (Xen)
• hardware assisted virtualisation - the CPU provides assistance to the above methods (KVM)

The programs above are only very roughly categorised, for example virtio provides paravirtualisation to KVM.

One of our puppet rules ensures that NTP (which ensures that the server has the correct time) is not installed on any virtualised guest images where the time is supposed to be taken from the host automatically. Unfortunately "facter" which should provide this information still hasn't applied patches submitted over 6 months ago. So we've rolled our own package instead for use on Debian Lenny.

When creating virtual disks for KVM you can use several methods. Most people use flat files in one of several formats - raw and qcow2 being the most popular. qcow2 files can compressed and also have "holes" (where unused space doesn't use up real space).

We recently converted some old systems from flat files to using logical volumes as it's the recommended approach these days.

If you are using raw flat files (use "qemu-img info filename.img" to find out) then you can just use "dd if=filename.img of=/dev/rootvg/logicalvolume".

As an update to the Qemu-KVM packages we now present 64-bit Debian Lenny versions for your enjoyment.

Drupal has also been updated to v6.14.

KVM is the "preferred" Linux virtualisation solution (at least as long as you have hardware support that is). Beware that the management tools for KVM are still fairly immature - VMware's vSphere product for example is still leagues ahead in terms of production usage.

Feature wise however, KVM is pretty good even if the libvirt abstraction layer support tends to lag a little behind.

Overview

Redmine is a powerful project management system. It is similar to the popular Trac, however it looks much more professional and is certainly easier to navigate.

Problem

There are no Ubuntu (nor Debian) packages of Redmine available, though some are in progress. Additionally as Redmine uses a Ruby on Rails framework, there are additional complexities ensuring that the Rails framework is current.

Howto

Rails setup