Until today I was clueless what the difference between
"Permissions database stored in mounted-over /dev" and
"Permissions database stored in normal directory" is.
Main problem was missing documentation of "mount --bind" as my old
mount man page did not mentioned it. I upgraded "mount" but "--bind"
is still missing in the man page. Just the command on its own gave a
One can also mount an already visible directory tree elsewhere:
mount --bind olddir newdir
Now I see the difference in both mentioned approaches - there is
nearly no one!
In the end (everything is mounted) both solution have their database
in /dev-state and devfs in (e.g.) /dev.
While unmounted you can see it this way:
-/dev is holding the database (and mountpoint, too)
-/dev-state is empty (mountpoint only)
-/dev is empty (mountpoint only)
-/dev-state is holding the database
I hope I'm correct here... If I am it would be good to mention this in
And as "mounted-over /dev" needs a new mount and recent kernel: what's