Forcing sapnfs package to halt last.

[Nick Stocker]

I am experiencing big problems in a new SAP ServiceGuard Cluster. As well as several SAP Packages I also have the sapnfs package containing the usual /sapmnt/ directories etc.

The main problem I have is that when the cluster is shutdown either via cmhaltcl -f or e.g. if failover of a node occurs, sometimes (not all the time) the sapnfs package goes down before some of the others and when this happens, the remaining packages hang and the halt of the node hangs because they can not longer access essential executable files etc..

I have already got sapnfs last on the cmapplyconf command as suggested by the SAPeSG manaual. More often than not this does the trick and sapnfs does go down last but as I say sometimes it doesn't.

The manual also suggests having a local copy of executables so that packages can still be shutdown if sapnfs is not there.

However this is not possible as the underlying mount point is inaccessible if sapnfs is shutdown unless it's allowed to kill all the processes holding onto that filesystem. I have configured alternate nodes in the automounter file but the system doesn't look at the secondary location as it's still got a hold on the main sapnfs one.

The main issue is the order of the sapnfs package. How can I force it to come down last?

Any ideas on this would be welcomed as I need all the help I can get and at the moment the cluster has not only a single point of failure but it can't be guaranteed to failover either.

Thanks
N Stocker

[skt_skt]

i am not sure how your other packages are related to your sapnfs package whihc could cause a hung to other pcakges. It looks to me there is common mount DIR(not exact mount point) shared by both the nfs and other pcakge(or some thing like that ...) whihch causing the hung.

We do have a similar nfs concept,but does not cause any problem to other package

[Joe Short]

The easiest thing to to id write a loop in the run/halt script for the package that will look to see of all other packages are down, and only shut down if thay are down first. You can use cmviewcl to determine the status of other packages. If all other packages are not down, the sleep for a while and check again.

[Nick Stocker]

Thanks for that idea - I have in fact already tried something like that but it didn't work. I think the probably being that when you run cmahaltnode or cmhaltcl packages go down one at a time so I think I just ended up with 'sapnfs' halting (and waiting....) and the others not doing anything at all.

[Joe Short]

Another, less elegant, option is to turn off autostart on all but a single package. Then use the one package to start and stop all others in a specific sequence. It work, although it can become more and more confusing as you add packages.