Problems with Configuring qla4010 Card when ESX Server Boots from iSCSI
Details
Why did my ESX Server lose connection to the iSCSI storage device?
Solution
Booting ESX Server from iSCSI, using the VI Client to set or change iSCSI HBA parameters, might cause ESX Server to lose connection to the iSCSI storage device.
Workaround: Do not use the VI Client to set or modify such parameters as IP address, iSCSI name, discovery information, or CHAP credentials for the iSCSI HBA that ESX Server uses to connect to iSCSI storage. Instead, set these parameters through QLogic BIOS Fast!UTIL.