Xen P2V for large physical hosts with much free space

Question

I need to P2V a rhel5 machine to xen under rhel5. I know I can use dd if=/dev/sda then using virt-install --import on the host, but the downside of this is the original machine has 80% free space on its drive.

Does anyone know of (or can document) a quick and easy method which works reliably, to produce a bootable xen image which can run under a hvm in such cases ?

I tried clonezilla to make the image, to avoid the free space problem, but it failed to do the clone with "something went wrong" (useless info, i know).

At the moment im looking at doing a dd of each partition, and a file level copy of the partition which is mostly empty, then creating a new virtual disk, copying the partitions over to it by mounting both the new image and the virtual drive on a second vm, then copying the boot sectors over, then copying the file level backup..... there must be an easier way ?

Oh, and budget is $0. :)

Answer 1

Use virt-p2v which is part of RHEL6 and Fedora 15.

It is a commandline tool that migrates from physical to virtual.

The author of virt-p2v have made many other tools in the virt- series. Check out his blog for cool howtos.

Answer 2

Seem to have found a kludge for this.

Instead of messing about with partition sizes and such, just dd the entire drive and use cp --sparse=always to make a sparse file version of the image. The dd still takes a long time, but it removes the need for vast quantities of space on the vm host, which was the original concern.