Lost Connection to Host, Unable to Add Host Datacenter.QueryConnectionInfo

Just yesterday I restarted management services/agent on a host to try to resolve an unrelated issue. After everything seemingly restarted ok. I could no longer connect my host to vcenter and I couldn’t directly connect to my host with the vSphere Client. It kept giving me an error to this effect…

The user account selected to connect to the host does not have sufficient permission to enable vCenter to manage the host.

Error Stack
“Call “Datacenter.QueryConnectionInfo” for object “Datacenter” on vCenter Server “vCenter41.domain.local” failed

After doing some research online and not really finding too much that was helpful for me specifically… I took a look at the services with a get-vmhostservice. From this I realized I didn’t see hostd(now I realize I wouldn’t see hostd anyway :)).

Fortunately I had both phsyical and shell access to the host and was able to restart the hostd service with  a   “/etc/init.d/hostd restart” command from ssh.

After hostd restarted everything started working again. I assume that rebooting the host would have fixed the issue as well, but I wanted that to be my last resort as I would have had to power off its VMs, since I couldn’t migrate them.