You might consider the following directories when doing your system backup:
/root
• main directory for the root user.
/home
• contains the user’s data files and user-specific configuration files. Each users has one folder with their username. Each user only has write access to their own home folder and must obtain elevated permissions (become the root user) to modify other files on the system.
/etc
• contains system-wide configuration files, not contain user-specific configuration files (normally located in each user’s home directory).
/usr/local/
• locally compiled applications install to by default (i.e. not installed through apt). If you have packages installed here, you may want to backup the whole directory, so you don't have to reinstall them. If the packages themselves aren't important to you, it should be enough to backup /usr/local/etc/ and /usr/local/src/
/boot
• contains the files needed to boot the system – for example, GRUB boot loader’s files and Linux kernels are stored here. However, the boot loader’s configuration files aren’t located here, though – they’re in /etc with the other configuration files.
If you found I miss out something, please leave your comment below. Cheers
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