Mounting an external parallel hard drive

Can anyone please walk me through how to mount an external parallel (or scsi) hard drive in visualize C3000 machine? I also would like to mount "/var/sallie" directory in that external drive. My "/var/sallie" directory is running out of space so I would like to mount an external hard drive so that I can mount my existing "var/sallie" directory into this new external drive.

Thx