How to sync directories between several computers

How to sync my home directories between my personnal computers

• Use case : let’s assume you have at least two pc’s, with personnal files in a home directory, and would like to have the same versions of your files on both computers. Your systems can communicate by ssh.

• Solution : synchronize your files with unison (cross platform solution).

• How to (very short) :

  • Install unison : with apt if under a debian like distrib. Otherwise, refer to you operating system packages manager. Bonus, unison was also available on windows.

    sudo apt get install unison
    

    Pay attention to the unison version : not all are compatible between them. The installation process might be developped more precisely in a further version of this post.

  • Choose the directory you want to sync. Since unison will browse every file before syncing (to determine wich is the most recent one), it can be a very long process if you try to sync .cache directories, or very large files accross the network.

  • Sync with the propers options : for exemple

    unison -auto -perms 0 ~/myLocalDir ssh://me@remotepc//home/me/myDistantDir/
    

    Explanations :

    • auto : reconcile changes automaticaly (otherwise you will be asked for each - … each what… I should check).
    • perms 0 : don’t touch file permissions (linux). Otherwise it will mess the rights between the two systems.
    • me : the user (you)
    • myLocal[Distant]Dir : self explanatory.