an install on top of that duplicates the data, and I ended up with 2 dcerouters, etc.
Classic.
Here's what I would do: When you install (K)ubuntu leave maybe 5GB of unpartitioned free space on the end of your HD. This will mean you have to setup the partitions manually, I think. Do an install. I would recommend just a / and swap partition, as it's easier. You can experiment with different/better layouts once you understand the process. (Since LinuxMCE modifies /home, /var, etc each partition would need it's own snapshot volume. Keep reading for this to mean anything
)
When (K)ubuntu boots up, enable Universe (and Multiverse?). Install the 'evms-gui' package.
Reboot from the Live CD again. Enable Universe (and Multiverse if you had to before) and install 'evms-gui'
Now, open a terminal and type 'sudo evms-gui'
When EVMS-Gui launches it will show whatever partitions you setup, but instead of /dev/sda1 (etc) they will show up as /dev/evms/sda1 (etc).
Right click on the partition that represents your / partition. Right click it and choose "convert to EVMS volume" Enter a name for the partition, such as "root"
Now right click on your /dev/evms/root partition and choose "Add Features to Volume." Add the "snap shot" feature.
Again, right click /dev/evms/root and click "Create snapshot" Choose your unpartitioned free space as the destination (you may have to first create an LVM container on that free space and choose the container instead...) Name the snapshot something like "snap"
Reset the snap shot (maybe not necessary, but good to know how to do) by clicking the "Featured Objects" tab and right clicking the snap object. Choose reset.
IMPORTANT, you now have to edit your /etc/fstab file and change the root device to /dev/evms/root. You may also have to modify /boot/grub/menu.lst
When you reboot, your root device will be running from the EVMS layer with a snap shot. When you make changes to your disk, the changes will be written to the snapshot partition instead of the real partition. When data is read, it is compared against the snapshot volume. If you "Reset" the snap shot, all of the changes are written to the actual partition and the snapshot is cleared, though it will collect new changes. You can roll back the snapshot, which will delete the change data and your root partition will look like the time you took the snapshot.
So, once you get it working (check the wiki.ubuntu.com, ubuntuforums.org, and evms user_guide for more info, I'm regurgitating this from memory) you can do an install of LinuxMCE, and if it doesn't work just roll back your snapshot!. Once is does work, and you're satisfied I'd recommend Resetting your snapshot and then booting from the live cd to remove the snapshot entirely. Otherwise, once 5GB of changes to the disk have been made (recording TV shows??) you're device will appear "full."
It's kind of complicated, and maybe not worth it, but it's better than using dd to make and restore images, IMHO.
Edit: You do not need to go back to the live cd to remove or reset a snaps shot. The only reason one needs the LiveCD again at this point is if they would like to reclaim that 5GB used for the snapshot partition. Thought I'd clarify.