You can monitor the Dell PowerVault TL4000 Tape Library using the Nagios check_snmp plugin. After setting the TL4000 to accept SNMP connections on v2 SNMP you can run the following command below. This queries for the status of the library as a rollup.
# ./check_snmp -H <IP Address> -C community -o .126.96.36.199.4.1.674.108188.8.131.52.1.0 -r3
SNMP OK – 3 | iso.184.108.40.206.1.674.108220.127.116.11.1.0=3
So this will query the tape library on the IP address and return the status as a number. 3 = OK, anything we want to know about so using the -r expression means you can enter a regex expression. This is a simple one, if its not 3, its not OK and we want Nagios to report an error!