I've been trying to understand how the SNMPD service in ESXi behaves, as I am somewhat confused by some things that I see.
We have an automated installation process, that at some point sets up SNMP, and finishes by doing :
Get-VMHost | Get-VMHostService | Where-Object {$_.Key -eq "snmpd"} | Start-VMHostService -Confirm:$false
The automation scripts even confirm the status later by writing the status of the service before and after that section of the installation process, and I have seen it change from False to True.
However later on we have some installation checks that audit the system. This does the following:
Get-VMHostService -VMHost * | Where-Object {$_.Key -eq 'snmpd'} | Sort-Object VMHost | FT VMHost, Label, Policy, Running -AutoSize
This more often than not indicates that the service is at least enabled (Policy = On), but not actually running.
VMHost Label Policy Running
------ ----- ------ -------
Host-1 SNMP Server on False
Host-2 SNMP Server on False
Host-3 SNMP Server on False
And yet, our system health monitor is getting traps when things are done like starting stopping VMs.
Tinkering from a Powershell session and webclient, trying several commands to check SNMP settings and operation, I will occasionally notice that the web client shows the SNMPD is running, and a rerun of the audit checks will agree.
What is the behaviour of SNMPD supposed to be? If I set it running explicitly during host setup, should I expect it to be running thereafter, or does it not get started at the next reboot, or does it start and stop as required?