System logging is not configured on host Esxi 5.1/5.5/6.5 Syslog Errors

Change Advanced Settings (This is suitable for older version 5.1/5.5)
Select the Host Server, Configuration Tab > Advanced Settings
On Clicking Advanced Settings, the Advanced Dialogue box will appear

Change Advanced Settings (This is suitable for version 6)
Select the Host Server, Configuration Tab > Advanced System Settings
On Clicking  Edit

Expand the Syslog entry This op

Setting Syslog datastore

The variable Syslog.global.logDir is used to define a VMFS datastore location. e.g. [datastore1]