In the last weeks I started to migrate my virtual machines to KVM. Until now, I used on two Servers VMware Server 2.0 on Ubuntu, which caused many problems with Disk I/O’s and performance problems. Either way, I prefer Open Source software whenever possible. KVM and libvirt, which I use to manage KVM, is in a quite mature state nowadays.
To convert the VMware images I used this How-To. This worked quite well for most of my Virtual Machines. But several had snapshots or were split into 2GB files. This cant be handled by qemu-img. I converted the files to single, flat disk file first using vmware-vdiskmanager. In the end, I wanted to have pre-allocated (single file) anyway, because it provides best performance:
$ vmware-vdiskmanager -r Ubuntu.vmdk -t 0 Ubuntu-copy.vmdk |