Win2K Server Partition or Folder mirror

Maybe I am not understanding what you are trying to achieve.

What exactly are you trying to mirror? What goal are you trying to achieve.

There are different types of mirrors. Are you trying to mirror the OS itself just in case it dies. Thisshould be done at the hardware level with RAID 1, Mirroring.

Or are you trying to replicate information in a directory to another machine? ie what ever is written to the d:\sites directory on server1 is written to d:\sites directory on server2.
This is called replication. It will depend on what type of replication you want to do. Do you want each machine to be able to write and delete and the changes take place on both machines.

Or is 1 machine going to be the master and the other one the slave, where you write and delete from the master only and the slave mirrors the changes.

Or do you have 2 DC's and you want to replicate domain information. This is done automatically already.

You mentioned a cluster so I have to ask again what information you are trying to share/make highly available by redundant servers.

I was assigned the above task recently and the following is what I did:
First I'm running Active Directry on Windows 2000 Servers, all server are Windows 2K Servers(not advanced server).
1. I used Varites Storage Replicator for Windows NT/2000 version 2.1 to replicate data in real time. It is replicating it to an offsite computer that is connected via VPN to the office. The replicated (target) computer has a cable connection. For the first of the replication I had it onsite so it took only 3-4 hours to replicate istead of a few days. From than on it can in theory (although I never tried it) replicate over a 56K connection.
2. I set up the remote computer (target) as an Active Dirctory domain controller.
With the above steps I have madesure that in the event our server fails I have another server ready in 10 minutes.
The reason we put it offsite is because we already have a lot of reduandacy onsite. The above was only done in case we have a disaster like a fire.
According to Varites you can also replicate Exchange 5.5/2000 servers and SQL servers since it works on the file level. However I don't know how you can restore Exchange when you only have the files althoug I assume it is possible if you have a backup of AD. SQL is very easy to resotre even if you have only the files (you just attach it as a new database). In our case we havn't done it yet for SQL nor Exchange.

Other solutions you may want to consider:
. Clustering. You can get 3rd party clustering solutions that don't require Advanced Server (I believe Varites sells one).