This guide can be used for formatting camera internal hard drives or compact flash medium, etc.
Open a command window (terminal).
telnet 192.168.0.9 #(If the default IP hasn't been changed. Or you can connect via 'ssh' using putty for example)
Alternatively you may just open the terminal in the browser - http://192.168.0.9/phpshell.php (change the ip if your camera has a different one)
This will show you a list that should include: hda, hdb, etc... if you have storage devices connected. If these devices have been partitioned, then you will also see in the list: hda1, hdb1, etc... Or if they have multiple partitions: hda1, hda2, hdb1, hdb2, hdb3, etc...
This will allow you to partition, or re-partition the hard drive, before it can be formatted. It is recommended to make one partition using the full capacity of the drive.
m (This shows the help screen) d (If you need to delete any previous partitions) n (To create a new partition. Follow the prompts and type 'p' and then '1', to make it the first primary partition, and then hit 'enter' twice to use the full capacity.) p (To show the new partition table that you just created on the screen, and verify that it is correct.) w (To save the partition table to the disk, and exit.)
Update: since release 8.0.9 cameras support 4K sectors disks, you may create a single primary partition (selecting n, then p, then 1) and agree to the prompted defaults.
mkfs.ext2 /dev/hda1 -m0 -T largefile4
This formats the drive with the proper file system. This will only work after the drive has been partitioned. -'m0' means that no space should be left exclusively to the superuser and -Tlargefile4 optimizes system for storing large files (and this is what is normally done with the camera). You do not need to add any extra parameters for the 4K sectors.
mount /dev/hda1 /mnt/0
This will mount your newly partitioned and formatted drive to 'Mount 0' so that the system knows where to look for it.
This is just a quick check to see that the camera can read the drive now. You should see just one directory called 'lost_and_found'.