How can I move the 'Users' folder from my main drive onto a new drive (which I just installed on my MacBook Pro by replacing the optical drive with a 2nd HD)?
The goal is to separate the application and system (main SSD) and the data (separate HD).
Edit: I have never used Unix and I would prefer a solution that uses OS X graphical UI.
First, mount your new disk to a standard mountpoint, like /mnt. Make sure that you have the required permissions to read, write, and execute files as yourself, not as sudo.
Now copy onto it the contents of /Users, preserving the files' attributes (the -p option).
cp -Rp /Users /mnt
Modify your /etc/fstab file to instruct it to mount the partition you just mounted at /mnt at the mountpoint /Users instead. Please notice that, contrary to some ridiculous rumors floating around, /etc/fstab is not deprecated in recent OS X versions, see for instance an excellent discussion in this very forum. Also, you most likely do not have an /etc/fstab file because in Mac there is no need for it, so you will have to create one.
Rename the old /Users folder to something easy to remember:
mv /Users /Old-Users
Reboot and check that everything is alright. If it is, erase the directory /Old-Users.
