Done some very interesting experiments with snapshot bash version recently. Although incomplete as yet, the basic commands work fine and can be easily customised (set temp paths, add to the rcync-exclude list, throw in a few zenity dialogs)
One problem here is cpu usage in the rsync and mksquashfs stages, particularly if using virtualbox. I got some total lockups and even sudden shutdowns due to overheating. The fastest box here is a single-core XP3200, old but normally not problematic.
I used top to monitor this, it showed the VM process itself hitting 100% at those stages (rsync and mksquashfs)
I did some reading and tried cpulimit, which seems to work. Not ideal as the hog process has to first be started, then identified and manually limited to, say, 75%. Difficult if a script, when it is ready, will start that process (although if in an open VM session, the VM itself can be limited before starting the script)
Any better ideas to deal with this issue? I'm really looking for an automated cli solution.