I installed the amd64 version of Ubuntu 12.04.3 a new Toshiba laptop (that had Windows on it). This instalation formatted and used the whole of the hard disk.
After various problems, I needed to re-install. So I decided to put my /home directory on a separate partition first. Using Gpartd, I shrank the main partition, created a new one, juggled my data onto the new partition, reinstalled Ubuntu on the old partition, restarted, edited /etc/fstab thus:
and restarted. All ok.
# /etc/fstab: static file system information.
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
# / was on /dev/sda2 during installation
UUID=16866923-a89d-4c9f-8222-e809b3985709 / ext4 errors=remount-ro 0 1
# /boot/efi was on /dev/sda1 during installation
UUID=136D-0C69 /boot/efi vfat defaults 0 1
# swap was on /dev/sda3 during installation
UUID=3620fc8f-cfa8-4aa7-9438-43dcd827efb4 none swap sw 0 0
# extra second data partition on /dev/sda4 created 8-Feb-2014
UUID=c8e24e24-36ff-4a99-99b7-ce032cabda77 /home ext4 errors=remount-ro 0 2
After more problems, I needed to re-install again! Ran the DVD again but this time I got a bit confused, because the options were different.
I'm not sure exactly what I chose, but I think I chose to put the bootloader on /dev/sda instead of /dev/sda1 or not format /dev/sda2 or both. I think that the installer offering me /dev/sda as the first option as location for the boot loader misled me.
Booting gave me:
and when I could finally get to see /var/log/installer/syslog
An error occured while mounting /boot/efi
Press S to skip mounting or M for manual recovery.
it was full of Fatal errors to do with efi, grub etc.
I installed again, putting the bootloader on /dev/sda1 and installing and formatting /dev/sda2 and not mentioning /dev/sda4 at all.
This worked fine and I could edit /etc/fstab again to mount /home on /dev/sda4.
The username I specified was the same each time I installed.
I was scared to specify /home as a mount point for /dev/sda4 at install time, even with "format" off because I didn't know whether it would
a) respect all my existing data
b) replace /home with a virgin set of data or
c) leave my existing data unless it needed to be overwritten by virgin data.
Hope this is useful.