1.2 (newer format in varying locations) or "none" indicating that
the kernel isn't managing metadata at all.
+ level
+ The raid 'level' for this array. The name will often (but not
+ always) be the same as the name of the module that implements the
+ level. To be auto-loaded the module must have an alias
+ md-$LEVEL e.g. md-raid5
+ This can be written only while the array is being assembled, not
+ after it is started.
+
As component devices are added to an md array, they appear in the 'md'
directory as new directories named
dev-XXX