Very Computer

Hi all,

I'm running a 4.3.3 F50 server that exports some file systems to a
4.3.3 S80 machine. Those machines are connected by a 2 way gigabit
ethernet network. Yesterday I had to get the server down for
maintenance and surprisingly the client machine stopped answering to
its clients, i.e., the applications that runs on that machine hung.

There is a known problem related to that situation ? It might be a
coincidence and the problem with the applications was not really
related with the shutdown of the nfs server ? I looked for related
messages on both logs but I didn't find anything.

Thanks in advance.
Xyko

I have seen similer behavior between an old E30 and an H50 with massive
storage.  No one, including IBM, has given me any explanation.

My workaround is to make it part of every planned outage to unmount all NFS
mounts on the remote machine before the other goes down.  After the outage I
again mount the NFS mount, and the problem is avoided.   Unless someone here
has a better answer, this is what I recommend.

I tried tuning parameters for NFS and the TCPIP stack, without maing the
problem any better or worse.  I have not tested since AIX was upgraded to
5.1 ML 3  from 4.3.3 ML 10 recently, but I do not expect  any change in
behavior.

LUCK!

Quote:> Hi all,

> I'm running a 4.3.3 F50 server that exports some file systems to a
> 4.3.3 S80 machine. Those machines are connected by a 2 way gigabit
> ethernet network. Yesterday I had to get the server down for
> maintenance and surprisingly the client machine stopped answering to
> its clients, i.e., the applications that runs on that machine hung.

> There is a known problem related to that situation ? It might be a
> coincidence and the problem with the applications was not really
> related with the shutdown of the nfs server ? I looked for related
> messages on both logs but I didn't find anything.

> Thanks in advance.
> Xyko

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Quote:> Hi all,

> I'm running a 4.3.3 F50 server that exports some file systems to a
> 4.3.3 S80 machine. Those machines are connected by a 2 way gigabit
> ethernet network. Yesterday I had to get the server down for
> maintenance and surprisingly the client machine stopped answering to
> its clients, i.e., the applications that runs on that machine hung.

> There is a known problem related to that situation ? It might be a
> coincidence and the problem with the applications was not really
> related with the shutdown of the nfs server ? I looked for related
> messages on both logs but I didn't find anything.

> Thanks in advance.
> Xyko

Hi,

I donnot know if this is what happened, but if the NFS filesystem is
mounted with attribute HARD and mounted under the / filesystem
some system processes (scanning the / filesystem) might wait for
the resource to come back (this is from an IBM document). As a
conclusion NFS filesystems under / should be mounted with
option SOFT.

If it "just" was an application hang its likely that the application
tried to acces the NFS filesystem.

Regards,
Andreas

i had the same problems in my LAN

the problem should only occur if there are any requests to the server or
an access to one of the mounted directorys.

the best solution is to use the automount deamon.
i use it and it works without any problems.

good luck

chris

--
PS: pls excuse my bad english