The example YAML in this section contains the line " - 'root=/dev/disk/by-label/dm-mpath-root'". This line causes nodes that do not boot from SAN disk to fail, and be unable to boot. For example, if you have a server that has local disk, as well as remote SAN disk, and you have installed OCP onto the local disk, when you add the line "root=/dev/disk/by-label/dm-mpath-root" the system is unable to boot becuase the "root" device is a local disk, and not controlled by dm.

It should be explained that adding the "root=/dev/disk/by-label/dm-mpath-root" is ONLY required if you are booting from a multipath/SAN disk. If you are booting from a local disk this line should be removed.

This should be applicable to all documentation around enabling multipath as a day 2 task.    

I believe this will happen every time    

    1. Build a node that boots from local disk, and then follow the steps in the documentation exactly. Allow the machineconfig to apply to a node
    2. Check the node, you will find that it has not booted due to a misconfigured "root" entry
    

    Node boot failure

    Node should boot normally, but with multipath enabled for SAN disks only

We ran into this issue with a PoC with Charter. They followed the steps exactly as documented, which caused node boot failures. In order to fix the issue we had to back out the machineconfig change, and edit the boot line to manually point back to the proper boot disk (a very manual process). Please feel free to reach out via e-mail for additional details as this is an edge case, and a little confusing to describe in a bug.