lk/data/unison.md

title, tags, requires

title	tags	requires
unison	backups synch	networking/ssh.md

Install unison on both machines, and make sure both have the same version of unison, with the same version of the ocaml compiler (the smallest difference will cause problems).

unison -version

Create the ~/.unison directory on both machines.

Make a job called backup:

job=backup

Here is an example job, which synchronizes the ~/music directory with a remote machine which has the same username.

echo "
auto = true
root=$HOME
root=ssh://${user}@${ip_address}/$HOME

path=music

ignore=Name *.flac
" > ~/.unison/"${job}".prf

Remember to specify ${ip_address}

The last command means it will ignore any file with a name ending in .flac.

Automatic Runs

The first command means this will run but also confirm which files will be deleted, and which will be transferred, us batch = true instead. Or you can deleted that line in the .prf file and run it with a flag:

unison -batch ${job}.prf

Set unison to run with crontab or a systemd unit file to have directories synchronize automatically.

Problem Solving

You will see data files summarizing what has happened in the ~/.unison directory. If something goes wrong, you may be prompted to delete these to start again.