This requires to have a SCSI DVD drive attached to an FCP-to-SCSI bridge which is in turn connected to an FCP adapter in your System z machine. The FCP adapter has to be configured and available in your LPAR.
Insert your Red Hat Enterprise Linux for System z DVD into the DVD drive.
In the dialog box that follows, select
SCSI as the Load type.
As Load address fill in the device number of the FCP channel connected with the FCP-to-SCSI bridge.
As World wide port name fill in the WWPN of the FCP-to-SCSI bridge as a 16-digit hexadecimal number.
As Logical unit number fill in the LUN of the DVD drive as a 16-digit hexadecimal number.
As Boot program selector fill in the number
1 to select the boot entry on the Red Hat Enterprise Linux for System z DVD.
Leave the Boot record logical block address as
0 and the Operating system specific load parameters empty.
Click the button.