Before you configure the iSCSI HBAs to boot from a SAN, first prepare your storage area network by checking the cabling and switch wiring and configuring the storage system.


If you use scripted installation to install ESX when booting from a SAN, you must take special steps to avoid unintended data loss. See VMware knowledge base article 1540.


Connect network cables, referring to any cabling guide that applies to your setup.


Ensure IP connectivity between your storage system and server.

This includes proper configuration of any routers or switches on your storage network. Storage systems must be able to ping the iSCSI HBAs in your ESX hosts.


Configure the storage system.


Create a volume (or LUN) on the storage system for ESX to boot from.


Configure the storage system so that the ESX system has access to the assigned LUN.

This could involve updating ACLs with the IP addresses, iSCSI names, and the CHAP authentication parameter you use on the ESX system. On some storage systems, in addition to providing access information for the ESX host, you must also explicitly associate the assigned LUN with the host.


Ensure that the LUN is presented to the ESX system as LUN 0. The host can also boot from LUN 255.

On storage systems that present volumes as multiple targets rather than multiple LUNs, the volumes are always presented as LUN 0.


Ensure that no other system has access to the configured LUN.


Record the iSCSI name and IP addresses of the targets assigned to the ESX host.

You must have this information to configure your iSCSI HBA.