Sometimes it may be required to do a full restart of agents and services on a VMWare ESX host. You could do a full reboot, but this requires all VMs to be shut down or moved to another host. Fortunately, it is also possible to do a complete restart of services on a host without affecting the VMs running on it.
There are two ways of doing this, depending on whether you have direct access to the host, through console or through a remote management system like HP's iLO or Dell's iDRAC, or have to do it remotely.
Note that using the Restart management agents function from the console is not the same as a full restart of all services.
Use this method if you have access to the host directly through console, or when you can use a remote management system such as HP's Integrated Lights-Out or Dell's iDRAC.
If you can't log on using the vSphere client or SSH, this is the only way to restart the services.
Remote access can be achieved through SSH, after which you can log in and run the restart command. If SSH is not enabled on the host, you can enable it through the vSphere client by logging in directly on the ESX host, or connect to your vCenter server/appliance. You can also enable the SSH service directly through console access.