Location of StatsMonitor.log
vCenter Server 7.0.x
vCenter Server 8.0.x
Log Location
vCenter 7.0: /var/log/vmware/applmgmt/
vCenter 8.0: /var/log/vmware/statsmon/
It has been observed that StatsMonitor.log may not be present in diagnostic bundles (vc-support) generated from versions prior to vCenter Server 7.0.x
For vCenter Server 8.0 U3, the absence of particular log directories and files is evident, which is attributed to the architectural change from the statsmon service to the observability service.