NFS and NIS interoperability weaknesses

[Jack Werner]

We are running HP/UX 10.20 on an HP 9000 K-Class Server, supporting several Oracle 7.3.x databases. We make extensive use of NFS to mount filesystems from another HP 9000 K-Class "disk farm". All underlying Oracle datafiles exist on local filesystems and are not accessed via NFS. However, a couple of the Oracle applications have objects that contain references to files on the NFS mounted filesystems. We also use NIS(yp) for logins. The NIS master is also served by the "disk farm" system.
My question:
In our case, is it the chicken or the egg?
If the "disk farm" starts having NFS problems can/will this affect NIS availibility?
Alternatively, can NIS problems affect NFS availibility?
Comment:
In my limited experience with shooting suspected NFS problems, I have had ro resort to a reboot to clear these (NFS instability) problems.

regards,
J Werner

[Kevin Wright]

One of the problems with NIS is if the Master NIS server is down, users can't login because the authentication server is down..which leads to clustered NIS servers.
If your mounting your /home dirs for example, and the NFS server which exports your home dir, you won't be able to login in that case either..

[Sridhar Bhaskarla]

Advantage of NFS and NIS together is when you use automounter to mount the filesystems. YOu can configure to automatically mount the home directories and other necessary file systems upon the user login on any of the systems in the NIS domain.

If you are not using NIS/NFS in this fashion, then I don't see any problems with your NFS setup. Problems with NIS server may cause login failures and occasional system hangs. As long as the NFS server is accessable irrespective of NIS server, you should be ok.

-Sri

[A. Clay Stephenson]

Normally, if you have slave NIS servers on the same subnet then you shouldn't have a problem. However (one gotcha and it is a big one) is the case of NIS handling the NFS automounter maps. If you are running under such a scenario then you need to make certain that you have a very robust NIS environment. The other decisions you need to make are NFS mount options mainly intr or nointr and hard or soft.
Man mount_nfs for those options and their meaning. Normally you should not have to reboot
in order to fix NFS problems - just stop/restart the NFS daemons.


Regards, Clay