The /boot Partition May Be Created on Network Storage on IBM System z
A known issue in Anaconda on IBM System z causes the /boot partition to be placed on an iSCSI disk if you do not explicitly configure this partition to be placed on a local drive (DASD). As a result, the system is unable to boot after the installation.
To work around this issue, specify a local drive for your /boot partition. When configuring storage using Kickstart, use the 'part /boot --ondisk=<local drive>' command to create /boot. If you are performing a manual installation, select only local drives in the Allowable Drives section of the Add Partition dialog. Do not use automatic partitioning.