It looks like your home directory has its own partition. You can either:
- resize the partition using gparted, just boot ubuntu live cd (dangerous)
- make a copy of your home folder on your root partition then disable the home mount in /etc/fstab
The output of this terminal command will show you usage/free space for each mount on your install.
df -h
gparted is a GUI program and simple to use but it is dangerous because you can kill partitions and filesystems.
If you use choice 2 then use the tar command to make the copy of your home filesystem. Your original home device will remain, it just won't be mounted (won't be accessible).
This link looks like a good tar example.
http://www.aboutdebian.com/tar-backup.htm
however you will want to backup and restore just the /home folder.
also look at the mount command in terminal.
man mount
here is a list of steps that come to mind.
become root sudo -i
go to root folder cd /
edit: forgot tar -p for preserve.
backup tar -zpcvf /home-backup.tar.gz /home
unmount home umount /home
or umount /home/<yourname>
restore tar -zpxvf /home-backup.tar.gz
comment out the home mount in fstab gedit /etc/fstab
look for something like ...
# /home/myname was on /dev/sdb2 during installation
UUID=11111111-1111-1111-1111-111111111111 /home/myname ext4 defaults 0 2
and comment it out using the hash #
char
# /home/myname was on /dev/sdb2 during installation
# UUID=11111111-1111-1111-1111-111111111111 /home/myname ext4 defaults 0 2
finally reboot.