Some combinations of option cards can result in failure to load device drivers and subsequent failure to mount file systems or configure network interfaces, and possibly failure to boot the system. This occurs in ESX only, not ESXi.
The ESX host requires "Low Memory," or the memory addressed below 4GB for the Service Console, device drivers and other data structures. The BIOS utilizes 2GB of this memory area for its own uses. With the large number of supported I/O devices, this memory can become exhausted in some situations.
VMware describes this problem in their Knowledge Base at http://kb.vmware.com/kb/1016239.
Use the following procedure to reduce the amount of memory reserved by the Service Console.
A new list appears.
A prompt with the entire line appears.
The configuration is complete but it is not yet permanent.