Mathew
My understanding is that 133 ATA drives are backwards compatible with 100 ATA drives. If your drives are configured as 2 separate volumes you can pull all the drives on one side and do a test using just one new drive. Power down the raid and remove all 7 drives from one side and label them so you know what order they were in. If both sides are raided together as one drive, you will need to remove all 14 drives to try this test. If Xserve Raid utility let's you format and use the one drive, it will should remain happy when you add all 14. You may also need to run a firmware upgrade to enable the controllers to see larger drives, do this before you experiment with new drives.
WARNING, I am not an expert at this, and what I am recommending SHOULD work. Make sure you have no vital data on your Xserve raid before you start mucking around with it.
Cheers
John Christie
