ppc64 RHEL7 diskful install does not set to boot from disk after os installation, so if the node was set to boot from net, after the diskful os installation, it will still try to boot from network.
This is caused by a code problem in xCAT::SvrUtils::getNodesetStates, it does not handle the case netboot=grub2, so the NODESETSTAT in /xcatpost/mypostscript is not set, then the postscript setbootfromdisk is not added to the list.
Fixed in 2.8.5 and 2.9.
2.8.5: commit eae580c867c447e99efc880d6e0f82156777e942
2.9: commit d7081292fc2e04bd4cf5acc5e93846f58392b674