This page describes the steps necessary for formatting a hard drive for use with DD-WRT. The easiest way to do this if you are familiar with Linux is to connect the drive to a Linux system and use fdisk to partition and format the drive.

First, please read the DD-WRT Tutorial for formatting and partitioning an external storage device.

In the case of the Open MediaHub HDD connected to a fairly high-end router, i.e., the Cisco Linksys E4200, only 3 partitions are necessary as follows:

Partition #	Size	Format	Label	Mount Point
1	1G	ext3	Optware	/opt
2	64M	swap	Swap
3	(default)	ext3	Data	/mnt

Note that partition 3, Data, uses whatever is remaining on the disk after partitioning which, in the case of a 1TB hard drive is 99.9% of the disk.

Make sure to label the partitions because when the drive is auto-mounted by DD-WRT it will be necessary to map the device ID to the label.