Xserve(s): should I reinstall OS X

I have 2 Xserve servers running OS X Server 10.6.4 with the following hardware configuration:

They each have Xserve RAID cards and drives. I have recently moved them from a data center, where they sat behind a pair of firewall devices and they had originally been configured for failover between the two machines. At the data center they had fixed IP addresses.

Now I have the machines set up at home, connected by Ethernet to an Apple Time Capsule that serves as my primary home networking device.

Finding and removing or disabling all of the legacy settings on these machines has proved daunting. I keep having conflicts that arise when I attempt to install new software and services.

So I thought I'd cast about for options and advice.

I have backups of all critical data these machines hold.

I primarily use these machines for parallel processing of Mathematica based applications (lots of number crunching). No web services, email, or anything like that.

Can anyone recommend a way to identify and remove or disable all of the legacy configuration and then set up the servers to to operate in their new simplified environment?

If not, do I need to wipe them clean, reinstall OS X, and configure them anew?

If so, how long does a reinstall take?

Do I need anything other than the original installation disks?

It's a good idea to reformat the machine, because who knows what all was run on it, and whether that may cause problems for you later or more so now. So it's a very good idea starting off from a clean slate - you will know what is installed, since you installed it.

In fact, I would never use a re-purposed machine without formatting it first. It's a security risk not formatting, and I would not want to chance my data etc on it. And since the machine was a server connected to the internet, there's even more reason to reformat it.

It will take you much less time to just start over than it would to go through potentially hundreds of thousands of files located on the system that could have been modified intentionally or maliciously.

A typical install of OS X usually takes less than 1 hour, usually around 35 minutes or so. Server may take longer, and all you really need to do is get it started which takes less than 5 minutes.

Additionally, you would not even need the original install disks, you can install any version of Mac OS X newer than what came with the server originally. Which might not be a bad idea since you are not really needing the features that a server version has to offer, based on what you said your were doing with the systems. But that really depends on what the Mathematica setup requires.

You can even just install the OS onto an external drive and set things up cleanly. If you find you need to boot back to the old configuration, it's just a short interruption. Plan on 15 to 20 minutes for the install. The configuration depends more on your familiarity - I'd spend 30-90 minutes on the first attempt and see where you get in that time.

Doing the install over is almost always worth the time in my experience. You can document what you have, get back to defaults and avoid having things running that are not required.

With 3TB drives so inexpensive, it's inexpensive in time and funds to not just back up the boot images to compressed images and restore onto the boot drives once you have a new image that suits your needs.