Time for Xen?
So Xen 4.0 is just out. I've been looking....
It seems that amongst a slew of new features there is a gem. They have finally come up with a memory overcommitment solution, called transcendent memory (tmem) (pdf explaination). Vmware uses ballooning to over allocate memory, where a guest in need of memory has to ask other guests to free some and hand it over. Tmem is supposed to be faster, as the pool of extra memory is kept under the control of the hypervisor, and the avtual VM's just have a bare minimum of allocated memory. It's production ready, but there is plenty of room for optimization, as the debug code is still present. We shall have to see what the benchmarks look like.
In other news there appears to have been some success in getting Xen to operate on a ZFS filesystem, and as zfs now supports block level deduplication and instant snapshotting, it's looking like this could be a very strong contender in the single server virtualization market - certainly for small businesses and other areas where the bulk management & complexity of vSphere is not required.
Other additions to version 4 are HA, live migration, huge performance boosts with the new network drivers and a completely new virtual hard disk implementation (blktap2) that allows snapshots to be taken without interrupting the VM.
All in all, quite exciting - especially if you include the fact that citrix xendesktop express is free (10 user vdi, no remote access)
Has VDI become feasible for small businesses?

How to set up a virtualbox client from the console.
VBoxManage createvm -name “Your VM” -register VBoxManage modifyvm “Your VM” -memory “128MB” -acpi on -boot1 dvd -nic1 intnet VBoxManage createvdi -filename “VM.vdi” -size 4000 -register VBoxManage modifyvm “Your VM” -hda “VM.vdi” VBoxManage registerimage dvd /full/path/to/iso.iso VBoxManage modifyvm “Your VM” -dvd /full/path/to/iso.iso VBoxManage modifyvm “Your VM” -vrdpport 3390 VBoxVRDP -startvm “Your VM”
Virtualbox linux kernel upgrade solution
Problem:
VirtualBox kernel driver not installed. The vboxdrv kernel module was either not loaded or /dev/vboxdrv was not created for some reason. Re-setup the kernel module by executing '/etc/init.d/vboxdrv setup' as root.
VBox status code: -1908 (VERR_VM_DRIVER_NOT_INSTALLED).
Solution:
sudo apt-get install linux-headers-$(uname -r) sudo /etc/init.d/vboxdrv setup
Virtualized windows apps running via 2X & vmware server on linux
Running Windows as a VM on Linux with VMware Server
This looks interesting, this guide reckons that you can run windows apps so they look native (like the next version of parallelis for macs) by using the (free) X2 client to serve them from a firtual server running in the background.
I'm going togive it a go this afternoon and I'll let you know how it all goes!
KVM: Kernel-based Virtual Machine for Linux
KVM: Kernel-based Virtual Machine for Linux Basically it runs a modified version of qemu that accesses the local resources via a kernal driver presented by /dev/kvm. All virtual machines run as processes in the host OS, and they run at near native speed. This is still under development, but with sequoia capital listed as an investor, this is one to watch.. Oh, and it's GPL .
Virtual Linux
Virtual Linux
Virtualization means many things to many people. A big focus of virtualization currently is server virtualization, or the hosting of multiple independent operating systems on a single host computer. This article explores the ideas behind virtualization and then discusses some of the many ways to implement virtualization. We also look at some of the other virtualization technologies out there, such as operating system virtualization on Linux.












