I want to boot linux (Mint 14) from an USB drive, but mount essential parts of the filesystem from the hard drive (/home, /usr, /opt). Is there a filesystem type that can be used within a sparse image file on a ntfs partition that can be mounted and used for live r/w operations?
I've seen another question and now know How to create a sparse image. But the questions only talks about on/off use for backups, essentially writing just once. Is this suitable for live use? Will such a sparse image shrink again when files are removed, or will it only grow? If not, are there alternatives? Are there file systems especially suitable for this, or is ext4 just fine?
Thanks for any help.