Go to the following and get a free account - then use the different tools for info on the OS. You should be able to find all the info you need. FYI - usually media not loaded means the tape wasn't in the tape drive. If you have more than one tape drive on the system OR there was more than one tape drive and one was removed, you may be using the wrong device as far as the system is concerned. Check that you are really on tape(4) as shown in your error.

http://support.sgi.com/irix/