Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rice!uw-beaver!Teknowledge.COM!unix!hplabs!hp-ses!hpcuhb!hpindda!jack@hpindda.HP.COM
From: jack@hpindda.HP.COM (Jack Repenning)
Newsgroups: comp.sys.hp
Subject: Re: hpux 6.5:  nfs mount from hell
Message-ID: <4310101@hpindda.HP.COM>
Date: 13 Mar 90 20:00:32 GMT
References: <2008@ursa-major.SPDCC.COM>
Organization: HP Information Networks, Cupertino, CA
Lines: 31

Note that the strategy of mounting things in /nfs/hostname protects
you from tripping over dead NFS mounts whenever you try to access a
plain file, but it doesn't necessarily protect you from tripping over
dead NFS mounts when you access a (live) NFS file.  In general, the
problem is that you may have trouble whenever accessing the hung mount
itself, or any other file or directory in its parent directory.

You can buy that kind of protection by not mounting other system's
root (so now we have two rules: never mount to your own root, and
never mount someone else's root).  But that's no consolation if you
actually need to get to the other system's root.  You could get this
protection by introducing a phantom level of directory: mount things
to "/nfs/hostname/root" and below (e.g., the other system's passwd
file would be /nfs/othersys/root/etc/passwd).  In this case, you would
only stumble across the hung mount when accessing othersys.

However, there are still an annoying number of meanings for "access"
that you might not have thought of.  For instance, if the hung mount
(or any sibling) is in your $PATH, it may get "accessed" while trying
to find a command that's really elsewhere, and it will get "accessed"
by every csh that ever starts.

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Jack Repenning - Information Networks Division,
		 Hewlett Packard Company
RFC-822:    jack@hptnjar.cup.hp.com
uucp:    ...!hplabs!hptnjar!jack
HPDesk: Jack REPENNING  /HP6600/UX
USMail: 43LN; 19420 Homestead Ave; Cupertino, CA  95014
Phone:  408/447-3380                     HPTelnet: 1-447-3380
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