nfs and submounts

Steven N. Hirsch (shirsch@ibm.net)
Thu, 20 Nov 1997 08:32:18 -0500 (EST)


Bill,

I'm still not having much luck with mounting both physical volumes on the
NFS server. The server has this in /etc/exports:

/usr/src air.steve.net(no_root_squash,rw,insecure,async) \
cy.steve.net(no_root_squash,rw,insecure,async) \
amd.fast.net(no_root_squash,rw,insecure,async)

/ air.steve.net(no_root_squash,rw,insecure,async) \
cy.steve.net(no_root_squash,rw,insecure,async) \
amd.fast.net(no_root_squash,rw,insecure,async)

On the client machine "air" I am using Linux autofs, with the following
map:

amd amd.fast.net:/
* &.steve.net:/
cy/usr/src cy.steve.net:/usr/src

If I do "cd /net/cy" on the client, it properly mounts the root of 'cy'
under /net/cy. If I then 'cd /net/cy/usr/src', the most bizarre
behavior begins. The first time, it mounted the /usr/src partition, but
the underlying / disappeared. Then, when I cd'ed back to /net/cy/usr/src,
it too was missing! Finally, it appeared as if I was trapped in a loop
where /net/cy/usr/src on the client recursively contains a 'net'
subdirectory, which contains... You guessed it, 'cy', etc, etc.

Giving up on automount, I moved to 'amd' where tried mounting by hand.
Doing:

mount -t nfs cy.steve.net:/ /net/cy

properly mounts the root. Then:

mount -t nfs cy.steve.net:/usr/src /net/cy/usr/src

mounts the child partition - whereupon the underlying root partition
becomes "empty". Doing an 'ls' in /net/cy/usr/src triggers a message that
shell-init, getwd and job-working-directory "cannot access parent
directories", although operations in the current directory seem to work.

If I cd up to the now-empty /net/cy, and do an ls, it cheerfully lists all
the contents of cy's /usr/src (!) directory but complains "permission
denied" after each item.

Something is getting terribly confused. I'm open to suggestions.

Steve