You do not say which unix you are using.
ioscan is an hp-ux command
If you are on hp, then yes ...
ioscan -fn would be the command
You do not want the 'k' option, as this pulls out what is in the kernel, you want a fresh scan as things may have changed.
You can use the C option to specifiy class ...
ioscan -fnCtape would show the tape drives
You cannot restart a library from the unix command line, you would need to either use the library web console if it has one, or power cycle it.
Martin
