I have cl0ned my Linux Manjaro drive. Two computers using it. And i want to keep the home directory in sync, but obviously not overwrite any configuration unique to each computer... I do not know what to skip and what to include. Do you have idea?
I think that as always simple task is very complicated, here is what i have tried:

1. After setting static LAN IP to each computer ✅. I have
2. copied SSH key to/from each computer to gain password-less access (not necessary step). ✅
3. have tried to copy package manager cache to my old secondary computer: rsync --progress -av /var/cache/pacman/pkg/ [email protected]:/var/cache/pacman/pkg/
Notice that i am using root user because i had no permission as normal user. And in order to do that, i had to edit destination SSH config: "sudo nano /etc/ssh/sshd_config" and uncomment PermitRootLogin line and set it to "yes". and "systemctl restart sshd" (again on destination PC)
After i have copied the ssh key (step 2) to a root user account, executing ssh-copy-id ... on source computer, i have changed "yes" to "prohibit-password" in destination sshd_config file. Good, now i can access securely even root account.
So copying pacman packages worked, and when i ssh into my older computer and ran "sudo pacman -Syu" it updated system without need to download packages from the internet. ✅
4. Now i am unsure which /home/user/ files i should skip from rsync and which other directories i may safely sync ❓

Someone advised one of the following two tools:
https://github.com/rdiff-backup/rdiff-backup
https://www.cis.upenn.edu/~bcpierce/unison/