Run a script after ssh login on the remote Linux box:
For a specific user, make sure that the rc file exist in the ~/.ssh/ folder.
If not:
touch ~/.ssh/rc

Edit the file:
nano ~/.ssh/rc

paste in erDetFredag.sh: (or what ever script you want)

If erDetFredag.sh should run for all users, edit: /etc/ssh/sshrc (not working?)

Disk usage for all drives
df -h --total | grep 'Filesystem\|^/dev'