The vsan-health service on the vCenter server fails to start and throws the following error: "An error occurred while starting service 'vsan-health'"

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• The vsan-health service on the vCenter server fails to start and throws the following error:  "An error occurred while starting service 'vsan-health'"
• vSAN related logs will not capture the actual error.
• vMon log will also give any hint on the failure. 
• Checking vmware-vsan-health-runtime.log.stderr gives the following trace

Starting service process with pid: 542.
Traceback (most recent call last):
  File "/usr/lib/vmware-vpx/vsan-health/VsanMgmtServer.py", line 382, in <module>
    SetupLogging(gCmdOptions, logdir)
  File "/usr/lib/vmware-vpx/vsan-health/VsanMgmtServer.py", line 194, in SetupLogging
    Logger.InitLogging(logDir)
  File "/usr/lib/vmware-vpx/vsan-health/logger/Logger.py", line 295, in InitLogging
    SetupLoggers(loggerConfFile, logDir)
  File "/usr/lib/vmware-vpx/vsan-health/logger/Logger.py", line 273, in SetupLoggers
    configInFile = UpdateFormatterHandlerPath(f)
  File "/usr/lib/vmware-vpx/vsan-health/logger/Logger.py", line 231, in UpdateFormatterHandlerPath
    config = json.load(configFile)
  File "/usr/lib/python3.5/json/__init__.py", line 268, in load
    parse_constant=parse_constant, object_pairs_hook=object_pairs_hook, **kw)
  File "/usr/lib/python3.5/json/__init__.py", line 319, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python3.5/json/decoder.py", line 339, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python3.5/json/decoder.py", line 357, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Environment

VMware vCenter Server Appliance 6.5.x
VMware vCenter Server Appliance 6.7.x

Cause

This issue can happen if the logger.conf file is corrupted

Resolution

To resolve the issue.

1. Change directory on the vCenter: cd /etc/vmware-vsan-health
2. Move the file logger.conf to another location.

mv logger.conf /var/tmp/logger.conf

3. Once done, try restarting the service with either of the following commands: 

vmon-cli -r vmware-vsan-health
service-control --restart vmware-vsan-health

Additional Information

Impact/Risks:

• VAMI based backups will fail since the service is stopped.
• vSAN monitoring information would not be available.