In my experience with troubleshooting, it is wise to copy-paste a copy of the original mdadm --create command in a commentary into the mdadm.conf file as well, it can sometimes be practical for recovery.
For example in the case of trying to recover a (partial) loss of 2 drives out of a raid-5 array (by recreating it). But if in the recreation process, for example a different chunk-size is being used, it's a no-go...
The best way to get used to recovery of a lost raid array is to use 3 or more usb keys (as simulating a failed drive can be easily done by unplugging it :-D Getting experience here, is advised prior to using this in production... ... especially because it works very well - as long as you don't mess it up ;-D
Greetings, Jasper
