Unable to consistently deploy overcloud nodes with Red Hat OpenStack 7.2

Issue

• Some deploy nodes stuck in wait call back during deploy

 +--------------------------------------+------+--------------------------------------+-------------+-----------------+-------------+
| UUID                                 | Name | Instance UUID                        | Power State | Provision State | Maintenance |
+--------------------------------------+------+--------------------------------------+-------------+-----------------+-------------+
| ************************************ | None | ************************************ | power on    | active          | False       |
| ************************************ | None | ************************************ | power on    | wait call-back  | False       |
|************************************  | None | ************************************  power on    | active          | False       |
+--------------------------------------+------+--------------------------------------+-------------+-----------------+-------------+

• Looking at the console output of the overcloud nodes stuck in wait call-back, the failure occurs during the install_bootloader phase of the dracut pre-mount script /lib/dracut/hooks/pre-mount/50-init.sh. The error returned is "mount: you must specify the filesystem type" "Failed to mount root partition /dev/sda on /mnt/rootfs"
• Inconsistent director deploy
• Deployment nodes sometimes fail to deploy when using 7.2 ramdisk and kernel images
• The ironic nodes often end up in the wait call-back state until the time out period has expired.
• Some nodes will deploy while others fail.
• Failed node's console shows "mount: you must specify the filesystem type" "Failed to mount root partition /dev/sda on /mnt/rootfs"
• Failed deployment node seems to be stuck on nc -l -p 10000
• Sample screenshot of failed overcloud deployment node: