After shutting down the QoreStor server for a power outage, on startup the NIC cards were not available. Upon logging in as root via iDRAC virtual console (or physical console), all the network interfaces were showing down.
Red Hat NetworkManager appears to re-create the network config files under /etc/sysconfig/network-scripts/ and renames the old files .old, and leaves them in the same directory. NetworkManager was still trying to load the old files in addition to the current files, which causes issues with bringing the interfaces up.
Red Hat bug:
Log in as root and move all the .old files out of the /etc/sysconfig/network-scripts/ directory and restart the network services:
This should bring the interfaces back up, and the server should now be available on the network.
This is fixed in a later Red Hat release. In the meantime the problem can be solved by editing the file /etc/init.d/functions and adding ".old" to the extensions to ignore. Search for __sed_discard_ignored_files and add the extension so the line looks like this: