@Sylvhem You also can use bind mounting. This solves a lot of problems :)
@Sylvhem it's basically mounting a directory in a mountpoint.
For example, you have /dev/sda3 mounted at /srv and a directory /srv/home
You can do mount -o bind /srv/home /home and you have the content of /srv/home in /home.
@laeti Thank you for the explanation!
@laeti Bind mounting? I never heard of that. I'll give it a look :).