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automount problems after DNS-Server Change without reboot ?

Kasper_USB
Frequent Advisor

automount problems after DNS-Server Change without reboot ?

Hello together

We changed the DNS-Server - Entry on our SAP-Clients.
Now we have some times problems with automount.

Should we reboot ?
Is there a hidden cache to empty ?
Should we restart automount and how ?

I attach the relevant log for more info.

Thanks for all help.

Olaf
7 REPLIES
TTr
Honored Contributor

Re: automount problems after DNS-Server Change without reboot ?

> We changed the DNS-Server

Did that also changed the nslookup outcome for any of the hosts? It would appear that it did and you have a hostname that now resolves to a different IP address and there is no response from that IP address. If the csappx1 is still up the restarting the NFS services might fix it.
Matti_Kurkela
Honored Contributor

Re: automount problems after DNS-Server Change without reboot ?

With HP-UX 11.11 at least, it looks like each process reads /etc/resolv.conf when it starts and never after that. If you have not restarted your NFS processes after the DNS server change, those processes will still be using the old settings.

The scripts to start/stop NFS services are all named "/sbin/init.d/nfs.*". There are three of them: one for services common to both the server and the client, another for server-side and the third for the client side. Automounter is one of the client-side services.

In other words:
First make sure all NFS mounts are unmounted. Then:

sh /sbin/init.d/nfs.client stop
sh /sbin/init.d/nfs.server stop
sh /sbin/init.d/nfs.common stop
sh /sbin/init.d/nfs.common start
sh /sbin/init.d/nfs.server start
sh /sbin/init.d/nfs.client start

should restart all NFS processes.
If your system has e.g. the NFS server component disabled, the server start/stop commands for it simply do nothing at all.

MK
MK
Kasper_USB
Frequent Advisor

Re: automount problems after DNS-Server Change without reboot ?

Hello Matti ttr

Thanks for the feedbacks.
I will try to repare it with restart nfs.
After that we will see the result.

Olaf
Kasper_USB
Frequent Advisor

Re: automount problems after DNS-Server Change without reboot ?

We have it done.

Reboot the complete system with the following result:

nfs automount is stable, but the mount of /usr/sap/trans takes 25secs -> too long for us.

We decide to mount via fstab.
(exclude from automount)
Dave Olker
HPE Pro

Re: automount problems after DNS-Server Change without reboot ?

Hi Olaf,

If a manual mount of the filesystem is fast but mounting via AutoFS takes 25 seconds then something is very wrong. AutoFS should be able to mount a new filesystem in well under 1 second. If you want to troubleshoot the AutoFS problem let me know. If you're happy mounting via fstab that's fine.

Regards,

Dave
Tingli
Esteemed Contributor

Re: automount problems after DNS-Server Change without reboot ?

Kasper_USB
Frequent Advisor

Re: automount problems after DNS-Server Change without reboot ?

Thanks all for the tips and help.

I proposed to do more intervention.
Cause it is a highly available system for our business, we can't intervent more the problem.

First we upgrade to 11.31 (v3).

Olaf