Seagate SeaTools for DOS is a free hard drive testing software that runs independent from your operating system. Seagate provide a iso file which needs to be burned to a CD. Considering that CD/DVD drives are fast disappearing, and most computers these days support booting of a USB drive, it makes life easier if the the iso get converted into USB bootable. It is actually easy to do it on a Mac using the following steps:

a) Download Seatools for DOS from Seagate site (http://www.seagate.com/support/downloads/seatools/)

SeaTools - Quick diagnostic tool that checks the health of your drive. Our Story Blog Open Source Partners. Support Downloads. Suggested searches. Products Solutions Innovation Support. Cloud & Edge Data Center Specialized Drives Personal Storage. SeaTools for Windows is a comprehensive, easy-to-use diagnostic tool that helps you quickly determine the condition of the disc drive in your external hard drive, desktop or notebook computer. It includes several tests that will examine the physical media on your Seagate or Maxtor disc drive and any other non-Seagate disc drive. Quickly determine the condition of the drive in your computer with this comprehensive, easy-to-use diagnostic. Download for Mac (10.6-10.9) Software.

Seatools For Windows

b) Open the iso file downloaded. Simple double clicking should mount the file on your desktop. Open the mounted folder, and extract the SeaTools.ima to your desktop.

c) Rename SeaTools.ima to SeaTools.img (Accept the warning dialog box)

d) Insert a USB drive that you will use. Note that any data on this drive will be completely erased.

e) Start your terminal window and find the USB drive identifier:

. Make sure that you get the correct disk identifier. In my case it was /dev/disk1.

Seatool For Mac

f) Unmount the usb disk folder using the following commands in your terminal window:

Seatools Bootable

g) Copy the contents of the SeaTools.img file to USB drive

That’s it. Your USB drive will now boot to SeaTools. One thing that I have observed with the SeaTools is that if you have set the drives to be discovered through AHCI mode in your bios, it might not always detect the drives. It is better to change the drive detection to IDE for it to work reliably.

For those looking to use the same procedure on a Windows machine, this link should help your out:
http://blog.nowherelan.com/2013/04/04/boot-seatools-off-of-a-usb-drive/ . For Linux and BSD, the procedure should essentially remain the same as Mac in principle, although the disk identifier & unmounting commands might be different. dd should work on all.