If you see this error when running esxcli command
Error interacting with configuration file /etc/vmware/lunTimestamps.log: Timeout while waiting for lock, /etc/vmware/lunTimestamps.log.LOCK, to be released. Another process has kept this file locked for more than 30 seconds. The process currently holding the lock is smartd(PID). This is likely a temporary condition. Please try your operation again
ESXi host showing as Disconnected in vCenter Server is a known issue in ESXi 6.0.
his is a known issue affecting ESXi 6.0.
Currently, there is no resolution.
To work around this issue, disable smartd daemon on the host.
To disable smartd daemon: