Checking Tasks & Events shows an operation timed out earlier in the morning when creating a snapshot of the server for a backup.

Powering off the server was also met with the same error as was the resetting the server. Migration was the only task that could be performed successfully.

The problem appears to be around there being insufficient bandwidth/resources to handle the request.

The solution is to ssh to the physical ESX server that the virtual machine resides on and restart the “mgmt-vmware” service as the user root.

service mgmt-vmware stop

Stopping VMware ESX Management services:
 VMware ESX Host Agent Watchdog[  OK  ]
 VMware ESX Host Agent[  OK  ]

Wait 30 seconds and start the service

service mgmt-vmware start

Starting VMware ESX Management services:
 VMware ESX Host Agent (background)[  OK  ]
 Availability report startup (background)[  OK  ]

The ESX server and any virtual machines hosted on it will disconnect from the Virtual Infrastructure/vSphere Client and can be reconnected by right clicking on the ESX server and choosing “reconnect”.

When it reconnects attempt the tasks that were failing earlier and they should now as intended (I had to power the server on because I had initiated a shutdown earlier via the operating system, the server will stay running without any interruption throughout this process).

This problem occurs on the following versions

• vSphere ESX 4.0
• EXS 3.5