[Beginner] Importing /home from different Distro (Manjaro to Pop_OS)
I had a dual boot I rarely used because reasons, one of them being that it was Manjaro and it kinda sort of borked itself and evey time I upgraded it asked me to make choices I had no idea what they meant.
I wanted to give Pop_OS a try so I went and nuked the Manjaro and set up the boot, root and swap of Pop_OS in its place.
Point is, I had the /home of Manjaro on a different location (The OS is on a SSD shared with windows and I put /home on a HD). I did not point Pop_OS to it at setup for fear of it being nuked (Will it nuke it? If not I guess I can do a new install and point it there?)
Can I link Pop_OS home to the old Manjaro home or do I need to take care of something (format it, remove some specific folder...).
I ask because I convinced myself the matter was trivial, but in the process of making sure the /home of Pop_OS was empty I ended up with a system hang and my passwords (both user AND root) being rejected and I had to reinstall the whole thing, so maybe there's more to /home than just a bunch of data?
Im not sure exactly how you borked it but you can generally just point the popos installer to your old home, it shouldnt format it unless its flagged for format during the install, make sure it isnt and you should be fine.
In Manjaro I went throught the hoops of setting it up and it worked flawlessly, I don't remeber the details but I assume it was in fact mounted at /home.
Pop_OS never mounted it at /home, I briefly accessed it through /tmp I believe, everything borked when I renamed /home into /home.bak and then I launched the file explorer, so it had nothing to do with my Manjaro /home mount...
Mounting the home partition at /home in the installer should work. Deleting the /home of the user you're logged in as isn't going to work because the applications you use to do it will most likely try to write something into ~/.local or .config, do it's never really empty. You could log into the root user though and do it from there.
Btw. It's not really beneficial to put your home partition on an HDD for the same reason. All Programs you use are going to have to access some hidden config or data files so it's going to slow everything down. (Also in case you use Steam, it installs all the games in ~/.local) A better way is to mount the HDD somewhere else and symlink your ~/Documents, ~/Pictures etc to the HDD.
Yea I'm aware, the point is I simply don't have enough space on my SSD, I guess you could make an argument if I'm going to have /home on a HDD I could have the whole OS on it then? I assumed I would still retain some kind of performance gain... If I do it though I'd then have two bootable disk and I'm not sure if that's legal and/or sane...
I guess I'll go the easy was and just point at the old /home during installation and see what happens :)
What worked for me: I used to have multiple partitions, one for each system (Pop!Os and Manjaro, in your case) and one for the /home directory. The only stuff stored there is your personal data and settings.
When you nuked your /home you must have destroyed something else.
Should be "trivial", yes. The central OS components (e.g. systemd or whatever) shouldn't care about anything in your home directories. Only apps that store your user preferences, user DBs, etc. there should. So you might have some old hidden directories that won't be used anymore, some that hopefully different versions of the same apps if applicable can migrate the data from, etc. But it shouldn't affect the general functioning of your OS.
It wouldn't be a bad idea to first 1. backup the home directory, in case any app data migrations mess things up somehow, and 2. create a user with a home directory path that didn't exist in the old dir structure, in case you need to login as that user to fix things (e.g. let's say your profile or shell resource script has something that a new shell version in the new distro doesn't understand and that keeps you from logging in).
By default, your home directory will be /home/{username}, so your new user will not have any of the data from that other if they are named differently. It is possible to change the location of your home directory. Or to rename the subdirectory within /home at the filesystem level, of course. You could also go through your hidden directories and rename stuff so apps just don't find their old data directories, before you mount the directory on /home or before you start the apps to which the data belongs.
Mount your home somewhere else for a moment (/mnt/tmp for example).
Review dotfiles in Pop_OS home (ls -a $HOME) and copy what you want to keep/don't recognize into /mnt/tmp
Delete everything in Pop_OS home to save space (or not, it should not be very big)
Edit /etc/fstab to mount your Manjaro home under /home
Reboot