ESX Server becomes temporarily unresponsive under a heavy I/O load through aacraid driver
Details
When you place virtual machines on a storage device with a controller that uses the aacraid driver, and when an excessive amount of I/O is generated during the operation of the virtual machines to the storage device, the ESX Server host might temporarily become unresponsive due to delays at the storage controller level. As a result, the Virtual Infrastructure Client does not respond to input and one of the following errors might be displayed:
VMware Infrastructure Client could not establish the initial connection with server "xyz". Details: The server took too long to respond .
VMware Infrastructure Client could not establish a connection with server "xyz". Details: Timeout retrieving server inventory.
Solution
Distribute the virtual machines over multiple storage devices or a SAN.