Making use of a second drive for extra space? Here's a quick run-down: 1) Make sure you know which disk is being formatted. First, second, and third drives will be /dev/sda, /dev/sdb, and /dev/sdc respectively. Check this with fdisk -l
[03:50:04] [[email protected] ~]# fdisk -l

Disk /dev/sda: 34.3 GB, 34359738368 bytes
255 heads, 63 sectors/track, 4177 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2        ...