I'm looking for backup software for the Linux OS. So that in event of a catastrophic failure I can get some systems back online fast.

So, I have a few questions.

Since each OS is built on specific hardware, I assume I need a backup image for each OS with each hardware variation to cover all bases. I use Dell computers so I have database boxes using Dell 6450's, 6650's, 6850's and 6950's.
Now within those server models I'm not sure each piece of hardware is exactly the same. In that case I guess I will need an image for every server period. Does that seem right?

What is the best OS image backup / restore software out there in term of dependability?

Have a look at Mondo rescue. It can be used after you've loaded the system to create a bootable CD/DVD to reload it later.

We even found on one our Dells that had a different drive configuration that a Mondo rescue disc we'd created on another Dell (same model) booted and loaded successfully there AND took into account the extra space provided by the second machine.

By the way - you can use "dd" to "ghost" things that "ghost" won't. I just did it a week or so ago to copy my 30 GB laptop drive to a new 60 GB drive because the version of Ghost the Windoze Help Desk folks use here doesn't understand NTFS. Once I had copied everything to the new partition I used Gparted Live CD to resize the NTFS partition to take up more space than the original drive had. Later I installed FC6 so it is now setup to dual boot between Windoze XP and FC6 (with XP being the default in Grub).

"Best" is subjective, and the parent topic of backups is a wide one, but for cloning check out ghost for unix.

http://www.feyrer.de/g4u/

On the subject of cloning, I found clonezilla also to be decent. It will even shrink down some other file systems like ntfs so that the image file is smaller ala ghost.

You can get even get an iso image that includes gparted also, choose what you want at boot time. Kinda sweet

Just an additional 2 cents.

Look at my sig for SLAX live CD equiped with tools for system rescue and archive. It has Partition image witch you can create an image of a partition and split it into more files so you can burn them to a DVD, or there is allways "dd"