Basic desktop, ASUS m4a785m, AMD Athon deneb quad core, 8GB RAM, two SSDs.

I have two SSDs, /dev/sda (60G), /dev/sdb (120G)

Both are GPT with /dev/sd{a,b}1 as type ef02, BIOS

I have a standard Ubuntu 11.04, with all my apps installed on /dev/sda2

I installed the simplest possible Debian Squeeze on /dev/sdb2, 8G ext2,
installed all the necessary packages, etc to get xen working and wrote a custom grub 40 file to add a Xen menu entry.
It boots and works just fine.

Now, I prefer to change the ext2 to either xfs on lvm, or btrfs.

Regardless, Google's been no help here. How do I make a simple backup?
Just fsarchive as I usually do?

I've fsarchived all of my machines, repartitioned, changed fstypes, etc. dozens of times, but never a with xen install.

I'd like two paths
1: I want a simple step by step to backup, convert fs to preferably LVM/xfs, but I'll settle for btrfs.

2: copy dom0 to new partition with LVM/xfs.

Please keep simple as possible and include any references to decent tutorials (NOT Xen general, but backup specific).

Xen is version 4.1

TIA