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Cannot write to NFS-mounted directories

I've got two Red Hat Linux boxes, running Red Hat 6.0. I can successfully mount an NFS directory on the client, and list the files, and display them. They all appear to have read-write priviledges, but I'm unable to edit a file, or write in any way to the NFS-mounted directory. This problem arises both as root and as an ordinary user. The NFS server has an /etc/exports file without tabs, and with a (rw) code immediately after the client name (no spaces). The machines as also linked in a NIS server-client relationship, running ypserv 1.3.6.94 (the ypserv 1.3.6.91 originally supplied on the RedHat CD didn't work properly with yppasswd).

A couple of oddities:
1. /proc/filesystems on the NFS server shows
ext2
nodev proc
iso9660
nodev devpts

I had expected to see nfs in there, yet nfs support is now supposed to be modular, so hoping that I don't have to rebuild the kernel (worry!)

2. The showmount command described in RedHat's NFS-Tips web document is missing from my machines.

I'm obviously overlooking something simple here. Many thanks in advance for any help.

ahoffmann

If you have an /etc/exports file, what did exportfs tell you?

> showmount .. is missing ..
Did you search with
find / -name showmount
for it?

doyston

ASKER

exportfs works fine, giving:
/aton_data lidate.nad.ac.ie

I've tried finding showmound with the find command, but no success.

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williacr

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ahoffmann

can you get the reverse address resolution on your server for lidate.nad.ac.ie ?

> Third, make sure that your user is being looked up from NIS and not the local /etc/passwd file, ..
has no impact on mount requests, if you files or NIS or whatever

doyston

ASKER

The user is definitely being looked up from the NIS password list (in fact the user does not even have an entry on the NFS/NIS client password machine file).

Could you clarify what you mean by 'reverse address resolution' on the server, as I don't fully understand you (Linux newbie here!).

Thanks

ahoffmann

assuming that lidate.nad.ac.ie is the client which requests the mount, could you do on the server:

nslookup lidate.nad.ac.ie

if it reports an error, lidate.nad.ac.ie must be listed in /etc/hosts *AND* /the resolver (etc/hosts.conf) must be configure to use DNS and /etc/hosts

doyston

ASKER

OK thanks- nslookup reports no errors, and correctly shows the DNS server as well as lidate.nad.ac.ie. Any other suggestions of things to try...?

ahoffmann

do you have a DENY clause in /etc/hosts.deny (please read man hosts.access)

doyston

ASKER

Problem solved: the fault was actually in the NIS part of the setup, not the NFS side of things. I'd forgotten to increase my group id number to above the minimum defined in the yp makefile. Once changed, everything works fine.