I've some older servers in desperate need of an upgrade, running RHEL3, that would could not get net-snmp to build with the diskio stuff turned on.
No problem, I added a work around script as detailed here:
I Can snmpwalk the .18.104.22.168.4.1.2021.13.15.1.1 tree on the old server, but the diskio stuff is not showing up on OpenNMS for the old servers. It's all working fine for the new servers.
Why would I be able to snmpwalk the data, but OpenNMS can not find it? And how can I help OpenNMS find it?