Add a usb external hdd to centos

[charlo]

I have a brand new hdd in a external usb casing not formatted how do I go about adding this drive to my centos 5.3 machine

[devils casper]

Create partitions and format those in any of Linux native filesystems like ext3, ext4 etc. You have to mount those partitions in CentOS.

You can use GParted Partition Manager to create and format partitions in new disk. Its available in LiveCDs of most of Linux distros. You can install it in CentOS through Package Manager too.