Automounter - need documentation on auto.master options

[Eur Ing Chris Green]

I'm having trouble working out how the automount daemon decides on
what remote filesystems it should mount.

I have worked out that it's the file /etc/auto.master that controls
what automount does but I can't really understand the syntax of that
file - the man pages are a little opaque/obtuse.

My /etc/auto.master has the following entries:-

    /misc /etc/auto.misc
    /net  -hosts
    +auto.master

(Plus quite a few unhelpfule comments)

I can basically understand the first line, that uses the file
/etc/auto.misc to automount CD drives and floppy drives.

I don't really understand what the "/net  -hosts" line does, I think
it means that you'll get automounted directories in /net from hosts
listed in /etc/hosts.  Anyway it isn't mounting the directory I'm
interested in.

What I really *can't* fathom out is that last line the "+auto,master",
it seems to be making automount mount all sorts of things but I can't
work out how or why.  I *think* it's saying that automount should get
an 'auto.master' file from the places defined in the
/etc/nsswitch.conf file which has:-

    automount:  files nis nisplus

but I can't get to find how this actually works and I can't get to see
what auto.master it actually uses.  The commadn line nis utilities
refuse to admit to there bing any automount information.  How can I
get to see what 'automount' information is available?

-- 
Chris Green