During cartridge entry processing, even if the library is online and operational to a given host, at least one device needs to be online, or had been online, to that host for the library to be able to send the cartridge entry attention interrupt to that host. If the library is online and operational, yet there are no online devices to a given host, that host will not receive the attention interrupt from the library unless a device had previously been VARYed online. To get around this, ensure that at least one device is online, or had been online, to each host or use the LIBRARY RESET,CBRUXENT command to initiate cartridge entry processing from the host. This is especially important if you only have one host attached to the library that owns the volumes being entered. In general, after you have entered volumes into the library, if you do not see the expected CBR36xxI cartridge entry messages being issues, you can use the LIBRARY RESET,CBRUXENT command from MVS to initiate cartridge entry processing. The LIBRARY RESET,CBRUXENT command causes the host to ask for any volumes in the insert category.