I had an issue with the HP hardware sensors not showing fans. Going through the process I checked the 1.3.6.1.4.1.232 OID for the fan. I was able to find the OID in MIBs and OIDs for HP servers 1.3.6.1.4.1.232.6.2.6.4. When I went to create the Universal device Poller I realized the OID was already marked as fan status. Looking into the issue I realized that all the servers that had the fan was missing only had one Proc installed. Calling HP they told me that when they only install one Proc they install it in bay 2 and run the fans for 3-6. With this I found that HP servers will only properly supply SNMP information for fans when fans are installed in fan bay 1. In the HP documentation it also validates this finding. To fix the issue I had to install fans in Fan bay 1. I hope this helps someone else that is missing Fan information in Orion.
