I found a lot of posts about changing mount points and I thought it was simple, but it failed.
Right now everything is on one partition. I want to change /home to /dev/sdd1.
So, I mounted /dev/sdd1 /mnt/extra and copied the contents of /home to it.
I tested from a terminal by sudo mount -t ext2 /dev/sdd1 /home
Seemed to work so I edited fstab and added the line
/dev/sdd1 /home ext2 defaults 0 2
However, when I tried to login it said my home didn't exist if I wanted to mount to / instead. Of course not . I switched to another tty and logged in as root. /home was not mounted and when I mounted it manually I could login again.
What did I do wrong? I looked around in /var/log, looked at boot (empty) dmesg .. which file should log errors about this issue?