Can't pass up great advice. I've done my share of upgrades and have personally experienced each and every one of these situations. Here are the highlights but please take the link for the full story.
1. DO have a "silent install" option.
2. DON'T make the administrative interface a GUI.
3. DO create an API so that the system can be remotely administered.
4. DO have a configuration file that is an ASCII file, not a binary blob.
5. DO include a clearly defined method to restore all user data, a single user's data, and individual items.
6. DO instrument the system so that we can monitor more than just, "Is it up or down?"
7. DO tell us about security issues.
8. DO use the built-in system logging mechanism.
9. DON'T scribble all over the disk.
10. DO publish documentation electronically on your Web site.
10 Dos and Don'ts To Make Sysadmins' Lives Easier: "CowboyRobot writes 'Tom Limoncelli has a piece in 'Queue' summarizing the Computer-Human Interaction for Management of Information Technology's list of how to make software that is easy to install, maintain, and upgrade. FTA: '#2. DON'T make the administrative interface a GUI. System administrators need a command-line tool for constructing repeatable processes. Procedures are best documented by providing commands that we can copy and paste from the procedure document to the command line."
