How to make HDDs and partitions mount at startup (instead of additonal drives showing as greyed-out, unmounted, after startup):

1. Open Terminal.

2. Switch to root user

(if you've never set up root previously).

3. Once as root;

(Create a backup of the fstabfile just in case something bad happens).

4.

(Note the UUID of the partition you want to automatically mounted)

5.

(The mount path directory, where the device will be attached.)

6.

opens the fstab file in your favourite text editor (replace leafpad as appropriate with gedit or whatever your favourite editor is called)

7. Paste in

(Replacing with the UUID from step 4 of the drive), and replacing fat32 with the format of the drive) I seem to recall other formats are something like: ext4,ext3,ext2,hfs,hfs+ and lastly ntfs-3

So, the final line might look something like:

Restart and the drive will always be mounted at startup. (A good option for internal drives that should always be available)