Excellent article. It's funny (in a bad way) that many people say "disk is cheap" until the day that tempdb or transaction log starts filling up and you actually put in a request for more disk storage. In a corporate enterprise envrionment, it's not as if the sysadmin can just drop what they're doing, run down to the local electronics store, pull a $200 drive off the shelf, and pop it in the server. You can blow through thousands of dollars worth of billable time and broken service level agreements just discussing the issue and waiting for it to happen.