After getting everything on my new LibreNMS installation set up (and a required reboot of ESXi) I found that the guest OS value of my VMs had been unset. This is what I see in the event logs:
2017-03-14 05:05:03 nine NULL rachel.domain.com (GuestOS) ->
2017-03-14 05:05:03 nine NULL rachel.domain.com (State) -> powered on
2017-03-14 05:05:03 nine NULL susanoo.domain.com (GuestOS) ->
2017-03-14 05:05:03 nine NULL susanoo.domain.com (State) -> powered on
2017-03-14 05:05:03 nine NULL mc.domain.com (GuestOS) ->
2017-03-14 05:05:03 nine NULL mc.domain.com (State) -> powered on
Initially these had been set properly (FreeBSD 11.0-RELEASE for rachel, Debian 8 for susanoo/mc). VMware tools (via open-vm-tools) are running in the guests.
Looks like there’s some weirdness going on with VMware. Running discovery.php specifically for vmware-vminfo gives this:
Modules status: Global+ OS+ Device
#### Load disco module vmware-vminfo ####
SNMP[/usr/bin/snmpbulkwalk -v3 -n '' -l 'authPriv' [SNMP creds] -OQUs -m +VMWARE-ROOT-MIB:VMWARE-VMINFO-MIB -M /opt/librenms/mibs:/opt/librenms/mibs/vmware:/opt/librenms/mibs/vmware -t 1 -r 5 udp:nine.domain.com:161 vmwVmTable]
vmwVmTable = No Such Object available on this agent at this OID
SQL[SELECT id, vmwVmVMID, vmwVmDisplayName FROM vminfo WHERE device_id = '5' AND vm_type='vmware']
>> Runtime for discovery module 'vmware-vminfo': 0.1610 seconds with 4232 bytes
#### Unload disco module vmware-vminfo ####
SQL[SELECT attrib_value FROM devices_attribs WHERE `device_id` = '5' AND `attrib_type` = 'poll_mib' ]
SQL[UPDATE `devices` set `last_discovered` =NOW(),`last_discovered_timetaken` ='0.693' WHERE `device_id` = '5']
Discovered in 0.693 seconds
