I recently moved my Ubuntu installation (10.10) from one hard disk to
another. I also installed Linux Mint on the new drive, which controls
the boot menu (on the old hard disk the boot menu was installed by
Ubuntu 11.10).

Previously when booting into Ubuntu an external hard drive on a USB 3
port automatically mounted, using its entry in fstab.

Now, when booting from the new hard disk (the partition was copied using
dd so it should be identical to the old one), it fails to mount the USB
3 disk.

Once Ubuntu has booted, I have to switch off the USB 3 drive, switch it
back on, and then run sudo mount -a to get it mounted. Before I do this
there is no way to mount it, it is not even listed in gparted.

So how can I get the USB 3 drive automatically recognised and mounted at
bootup as before?


David K