ESX supports iSCSI technology that allows your host to use an IP network while accessing remote storage. With iSCSI, SCSI storage commands that your virtual machine issues to its virtual disk are converted into TCP/IP packets and transmitted to a remote device, or target, that stores the virtual disk.

To access remote targets, the host uses iSCSI initiators. Initiators transport SCSI requests and responses between the host and the target storage device on the IP network. ESX supports hardware, dependent and independent, and software iSCSI initiators.

You must configure iSCSI initiators for the host to access and display iSCSI storage devices.

iSCSI Storage depicts different types of iSCSI initiators.

iSCSI Storage
The graphic depicts two types of iSCSI connections, one with a software initiator, another with a hardware initiator.

In the left example, the host uses the hardware iSCSI adapter to connect to the iSCSI storage system.

In the right example, the host uses a software iSCSI adapter and an Ethernet NIC to connect to the iSCSI storage.

iSCSI storage devices from the storage system become available to the host. You can access the storage devices and create VMFS datastores for your storage needs.

For specific information on setting up the iSCSI SAN to work with ESX, see the iSCSI SAN Configuration Guide.