You can use either an HBA or a software-based iSCSI initiator in VMware. To enable and use the iSCSI initiator, you do need to use the VMware Infrastructure Client to configure a few parameters on the server. The process is somewhat lengthy, but it is fairly well documented in the iSCSI SAN Configuration Guide, which you’ll find at VMware’s Web site. The condensed version is that you need to create the network components to handle the iSCSI traffic, enable the software iSCSI initiator, and configure the iSCSI target discovery and CHAP parameters for your environment. In my tests, after I configured the appropriate IP address for target discovery and CHAP secrets, I still had trouble finding my iSCSI storage. I found a separate piece of documentation that told me I needed to open the software iSCSI firewall port by going to the Security Profile on the Configuration tab.
 
Once the iSCSI initiator is properly configured and the appropriate port is open, you can go to Configuration, Storage Adapters, right-click the iSCSI software adapter, and choose Rescan. After a few seconds, you should see a list of the available iSCSI targets to which your VMware server has access. When you get to this point, you’re on the home stretch. Click Storage from the Configuration tab, and run the Add Storage wizard by clicking Add Storage. In the wizard, select the Disk/LUN storage type and choose one of the SAN targets you created for VMware usage. Name your new data store, and you’re ready to copy or create VMs to your SAN volume.