Upgrade RAID array

You will need to back up the existing array then swap all the disks before rebuilding the array. I can think of no shortcuts here and am assuming your configured at raid5

If you are lucky you have a your boot drive seperate from the array. If so and you are running raid 5, you can upgrade your three drives one at a time to larger drives. Down system remove 1st small drive install first larger drive boot in to the array config utility select rebuild for the new drive. Once done with that one bring system backup, the down it and do it again with the next drive...etc untill the three drives are done then you will still have your normal array just build another array out of the extra space you now have available. Just can't do that on your boot drive. So if one of the three have your boot partition on it won't work.

I have a similar issue with an extra twist. The server is physically located across the country. What I'm thinking about is building the array using a similar machine then shipping just the drives to the office where the server is located. Can anyone think of any possible gotchas?