I personally find iSCSI to be an overrated storage solution; there are so many better, more managable options out there.
RHEL/CentOS 5.3 and iSCSI Targets
Strongly recommend grabbing the enterprise iSCSI target package from ATrpms. Direct link to the package listing is: http://atrpms.net/dist/el5/iscsitarget/.
The scsi-target-utils package distributed with RHEL/CentOS 5.3 is okay for simple stuff, but definitely out of date. And it completely fails when attempting to boot diskless systems via iSCSI over Infiniband. Spent quite a bit of time tonight attempting to figure out why BoIB 2.0.0 with a ConnectX card refused to communicate with my apparently working (export connectable/useable on other machines) iSCSI volume. Replaced tgtadm with the enterprise iSCSI target, and boom – instant satisfaction.
Note: Still working out comments/etc. theming. Please ignore the ugliness.