Managing Serviceguard Extension for SAP, December 2007

SGeSAP Cluster Administration
Change Management
Chapter 6300
If the system is badly configured, it might be possible that the system
hangs if a logon is attempted as <sid>adm user. The reason for this is,
that /usr/sap/<SID>/SYS/exe is part of the path of <sid>adm. Without
local binaries this directory links to /sapmnt/<SID> which in fact is
handled by the automounter. The automounter cannot contact the host
belonging to the relocatable address that is configured because the
package is down. The system hangs. To avoid this, always keep local
copies of the executables.
NOTE If the database package with HA NFS services is halted, you cannot log
in as <sid>adm unless you keep a local copy of the SAP binaries using
sapcpe.
To allow proper troubleshooting there is a verbose package startup log in
the package directory. It should be checked first in case of trouble. The
level of information can be adjusted by changing the parameter
LOGLEVEL in the sap.config file. If problems with package startup
remain, a general debug mode can be activated by creating a file
touch /etc/cmcluster/debug
The whole SGeSAP node will now be in debug mode. If the file is created
in the package directory /etc/cmcluster/<SID>, it will only turn on the
debug mode for packages in that directory.
The debug mode allows package start up to the level of SAP specific
steps. All instance startup attempts will be skipped. Service monitors
will be started, but they don’t report failures as long as the debug mode
is turned on.
In this mode it is possible to attempt manual startups of the database
and/or SAP software. All rules of manual troubleshooting of SAP
instances apply now. It is possible to access the application work
directories to have a look at the trace files. After removal of the error
cause it is vital to remove the debug file that got created:
rm /etc/cmcluster/debug
If the package still runs, all monitors will begin to work immediately and
the package failover mechanism is restored.