My server for Blue Sky On Mars is running on Fedora Core 3. I’m not in a rush to upgrade to FC4, but I know that such an upgrade is inevitable. Since the server is remote, thousands of miles away from me, I’m interested in doing the upgrade via yum. Apparently, it can be done, but there are potential gotchas. Thankfully, those gotchas have been enumerated here: YumUpgradeFaq.