[KLUG Members] NFS and time travel (repost)

[Robert G. Brown]

Over the last few days I've been examining how to employ NFS to improve
the integration of data around here.

Setting up NFS is actually quite simple; my biggest problem until now has
been that there were some cases where the same user name had different uid
and guid numbers on different hosts. While it looks like there are NFS
options that can deal with this, I decided to rectify this; a great example
of using the find command. Once done, a range of Linux boxes (RH 7.x through
9) seem to cooperate quite nicely running NFS...

While some might claim that extensive use of find is in of itself a form
of time travel, it's not enough for me; I have something better...

I have one machine here that is still running Red Hat 5.2 (that's a 2.0.36
kernel), which came out in the middle of the second Clinton administration.
It's been quite stable and a great performer, but somehow even I am coming
to believe that its best days are behind it. If it weren't for the ease 
with which NFS was set up, and the fact that I'd like to evolve where the
11 GB of data on it is going to go, I'd simply use the backups of all this 
stuff and rebuild it.

But first, I thought it would be interesting to see why it's so hard to get
NFS to work with the other hosts, because it doesn't. My question really is:
Why? I would think it would interoperate seamlessly...

The details
===========

The old system is called "harpo", and the much new system is called "gummo"
Both are running the nfs daemons that shipped with the OS....

[root@gummo root]# uname -a
Linux gummo 2.4.20-20.9 #1 Mon Aug 18 11:45:58 EDT 2003 i686 i686 i386 GNU/Linux

[root@gummo root]# rpm -q nfs-utils
nfs-utils-1.0.1-3.9

[root@harpo /root]# uname -a
Linux harpo 2.0.36 #11 Sat Dec 27 22:35:02 EST 2003 i586 unknown
# Just compiled, same as the kernel that's been running for years on harpo, 
# which was cut down from the stock kernel to match hardware, made monolithic,
# but with NFS enabled

[root@harpo /root]# rpm -q nfs-server
nfs-server-2.2beta40-1
# Apparently some reorganization has taken place which makes this version
# number hard to compare with the more recent "nfs-utils" package.

and you might be interested in....
[root@harpo /root]# cat /etc/exports
/home/bob       gummo(rw) groucho(rw)
/mnt            gummo(rw) groucho(rw)

[root@gummo root]# cat /etc/exports
/home   leppo(rw) groucho(rw) harpo(rw)

here's the punchline....

root@gummo root]# mount harpo:/home/bob /harpo
mount: harpo:/home/bob failed, reason given by server: Permission denied
# Response here is instantaneous.
# /etc/hosts.allow and /etc/hosts.deny (on both) have nothing in them
# but comments.

AND....

[root@harpo /root]# date;mount gummo:/home /gummo;date
Sun Dec 28 00:21:13 EST 2003
mount: RPC: Port mapper failure - RPC: Timed out
Sun Dec 28 00:23:13 EST 2003
# I include the date commands to show the timeout interval... 120 seconds...

It looks like harpo is not able to play the role of either client or server
right now, although these are to a great degree independent functions. This
leads me to think that perhaps NFS is just not compatible between RH 5.2 and
RH 9 boxes, which is something of a real surprise.

Am I going too far in time (5.2 <---> 9) with NFS, or is there just something
that I have overlooked?

							Regards,
							---> RGB <---