It will be basically the same boring stuff. Patching softwares, updating virus definitions, scheduling backups, database integrity checks, user administrations, troubleshoot level 1 and 2 problems, try to solve higher level problems with your manager or the vendor, etc etc.

For example: How do you troubleshoot a problem where a user cannot log on to windows? You have a Linux server that is not talking to a Windows NT server, where might the problem lie?