I installed Lion on a new disk today and let the migration assistant move users, applications and stuff from my internal disk to the SSD connected via FW800. So far everything works great.
Because I have a pretty large photos and audio library, I want to leave my user's home directory on the old Volume and have OS and Applications on the other disk.
To achieve this I opened up
Terminal.app, sudo'd and entered the following command:
cd /Users mv mwidmann mwidmann_ ln -s /Volumes/Macintosh\ HD/Users/mwidmann . chown -R mwidmann:mwidmann mwidmann
So far so good.
In finder the home folder was replaced with mwidmann_, but I removed that item from the sidebar and added the new one instead. Same goes for documents, downloads, pictures, videos, music. Other items I added there, worked like before.
Why I feel that I'm missing something is because the nice sidebar and dock icons for these "special" folders aren't showing up.
There must be an additional thing that tells Lion that THIS is my home folder and it is in
/Volumes/Macintosh\ HD/Users/mwidmann and nowhere else.