ESXi may fail to read the system power meter or other system health sensors via IPMI.  The message "ipmi_completion: no reply, failed to communicate with bmc" appears in syslog.log.

syslog.log
xxxxxxxxxxxx:01:23Z sensord[2100089]: ipmi_completion: expected at least one byte/completion code to be returned, retries left: 10
xxxxxxxxxxxx:01:43Z sensord[2100089]: ipmi_completion: no reply, failed to communicate with bmc
xxxxxxxxxxxx:01:48Z sensord[2100089]: ipmi_completion: expected at least one byte/completion code to be returned, retries left: 10
xxxxxxxxxxxx:02:08Z sensord[2100089]: ipmi_completion: no reply, failed to communicate with bmc
xxxxxxxxxxxx:02:13Z sensord[2100089]: ipmi_completion: expected at least one byte/completion code to be returned, retries left: 10
xxxxxxxxxxxx:02:33Z sensord[2100089]: ipmi_completion: no reply, failed to communicate with bmc
xxxxxxxxxxxx:02:38Z sensord[2100089]: ipmi_completion: expected at least one byte/completion code to be returned, retries left: 10
xxxxxxxxxxxx:02:58Z sensord[2100089]: ipmi_completion: no reply, failed to communicate with bmc
xxxxxxxxxxxx:03:03Z sensord[2100089]: ipmi_completion: expected at least one byte/completion code to be returned, retries left: 10

 

The issue has been resolved in ESXi 7.0 U3d.