SUMMARY: SunOS 4.1.3 can't mount files exported from an IBM server

From: Danton Nunes (
Date: Thu Feb 25 1993 - 08:06:20 CST

10 days ago I called for your help:
> From danton Mon Feb 15 09:50:43 1993
> Date: Mon, 15 Feb 93 09:48:58 EST
> From: danton (Danton Nunes)
> To:
> Subject: SunOS 4.1.3 can't mount files exported from an IBM server.
> Cc: danton, juan, banon
> Dear sun-managers,
> We have a network (actually three networks, two ethernets and a
> token-ring) comprising Sun and IBM workstations. Four machines, two
> from each brand, serve as NFS file servers. The Sun file servers are
> running SunOS 4.1.1 and the IBM's are running AIX 3.2.
> Everything was allright until last week when we installed new Sun
> machines running SunOS 4.1.3. The new machines could not mount the
> directories exported by the IBM servers, although they mounted
> correctly those exported by the Sun servers.
> The error message returned was: 'access denied'. This is kind of weird
> because the IBM servers have no file export restrictions. Needless to
> say, the workstations running SunOS 4.1.1 mount the directories
> exported by the IBM servers correctly.
> Where is the bug? Who should I blame, Sun or IBM?
The problem is now fixed. It was related to name translation by the NIS
aka yellow pages. Although the new machines had been added to the NIS
database on a master server the new data was not Xferred correctly to a
slave server. This slave server was answering the queries from the IBM
file server so the file server received wrong answers when it tried to
translate the IP addresses of the new machines into names.
The reason why the slave server failed in transfering data from its
master was shortage of disk space. Deleting some /tmp garbage was
enough to fix the bug.
Thanks for the following people for the answers: (Tim Evans), who suggested:
> Try putting fully qualified hostnames in your hosts file or NIS maps.
I did in the hosts files and it worked. Reason: the server used the
domain name service instead the NIS to translate names.
From: (Scott Crosbie)
> We have an ibm file server running aix3.2 serving a network of suns running
> 4.1.3 with no problems. We use the sun automount setup so that
> /tmp_mnt/usr/users2 gets mounted fine from the rs6000. If you do not
> use automount, you may want to try. It is very simple to setup and is handier
> than regular sun mounting. Good luck.
Automount has the same problem concerning names as regular mount.
From: (Guy Harris)
> Are you sure the AIX machine knows the host names and IP addresses of
> the machines running 4.1.3? nFor example, if it's not using NIS, it could
> be that it knew about the old machines, but didn't have its "/etc/hosts"
> file, or whatever, updated to know about the new ones.
Yes, that was the point. The server was mistranslating names because its
NIS server had not xferred data from the master.
From: Christian Lawrence <>
> sounds like a permission thing (prossibly different for security ??). check
> all the directories for correct ownership/privileges.
I checked these files and they were allright.
From: (Hao Wang)
> I used to have the same problem when I try to mount the file system which
> exported from NeXT server. But after I reboot the NeXT, it works. So I say
> try reboot the AIX then mount. Hope it works and good luck.
This again may have to do with name translation. Rebooting the server
made it reread the hosts table. Possibly a SIGHUP to the init process
could be enough.
From: (Andrew Rakowski - USU - RS/GIS Lab)
> Even with no export restrictions, hosts will do a "gethostbyname" (or
> is it "gethostbyaddr"? I don't remember the way the mount request
> protocol works right now...)to see "who" is mounting. If the call
> fails (can't figure out where the new host is), then the mount will
> fail. In any case, the hosts have to know each other by name for the
> mounts to work.
It is "gethostbyaddr". You were right, the problem was really related
to name translation by the NIS.
> I've seen this problem and I think I have a fair idea of the source of
> the problem but no fix. In my experience, when the IBM's CPU is busy,
> like at 100% utilization, it doesn't let Suns at its exported file systems.
> We tryed this several times with an RS 6000 which runs quantum chemistry
> jobs these often keep the CPU busy for hours or days on end. We found
> that even if you mounted the file system from the IBM when the machine
> was idle as soon as it ws busy again it would stop responding. I suspect
> that this is a problem at the IBM end of things. But I have no work around
> which would be acceptible to the general public.
Our server was not too much loaded so that was not the cause of my trouble. (Andy Feldt) and (Michael
Moscovitch 2764) reported they have no problem in similar situation.
Anyway thanks their 'good luck' wishes.

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