How can a machine be securely migrated from "Ubuntu - single partition - home directory encrypted" to "Debian - separated partitions for OS and home, and maybe for swap too if that is an advantage - with either encrypted home directory or full-disk encryption"?
- no free space available to make copies of the home directory for triangulation
- triangulation through external hard drive possible but very undesirable
- passwords don't change
I'm not experienced with repartitioning or fiddling with encrypted homes, so I'm worried about the order of things and dealing with all those problems at the same time. I'm thinking
- first a backup of most important files, although it wouldn't be possible to back up everything, then a repartition is made by booting with a Live CD, then new OS is installed and then home is already encrypted in the separate partition, nothing to change. But I'm not sure if this is correct, or if there areb't important details that could end up in data loss
- full-disk encryption is an improvement but I recall reading there're still serious issues in the setup (like risk of irreversible damages), so if this is not true, then FDE is better, otherwise encrypted home directory is good enough, but in any of the two cases I'm unsure how to proceed
How to do this in a simple way?