Excellent guides indeed. What you could have done though is be more detailed with other options for the creation of filesystem (creating a RAID 1 Mirror guide) and also include a final guide how to recover the RAID from an OS loss (probably conf files to be backed up externally in order to place them again to the same path in order for the OS to see the RAID, any commands need to be issued…etc

Then you will have the most complete RAID mdadm guide out there.

Thank you