You are troubleshooting a problem reported by other administrators in which the vCenter Server indicates that one ESXi host is not responding. The VMs on the host are also marked as not responding in the vSphere Client, but end users report that they can still access these VMs. You need to correct this problem without interrupting the VMs.
To accomplish this task, the administrator can perform the following steps:
/etc/init.d/hostd restart
/etc/init.d/vpxa restart