Managing Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64), April 2009

as needed. Servers outside of the cluster that have External Dialog Instances installed are set up in a similar
way. Refer to /etc/auto.direct for a full list of automounter file systems of Serviceguard Extension for
SAP on Linux.
It enhances the security of the installation if the directories below /export are exported without root permissions.
The effect is that the root user cannot modify these directories or their contents. With standard permissions
set, the root user cannot even see the files. If changes need to be done as the root user, the equivalent
directory below /export on the host the package runs on can be used as access point.
If the Serviceguard Extension for SAP on Linux package (sapnfs) of the NFS server host is not available it
is possible that the logon will hang if it is attempted as <sid>adm user. The reason for this is, that
/usr/sap/<SID>/SYS/exe is part of the path of the <sid>adm user. This directory is linked to
/sapmnt/<SID>which in fact is handled by the automounter. If the (sapnfs) package is down the
automounter cannot contact the virtual host of that Serviceguard package (the virtual IP address is disabled
when the package is halted). This is the reason why a local copy of the SAP executables is kept on each
cluster node.
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 the level of information logged can be adjusted by changing the parameter
DEBUG_LEVEL in the sap.config file. If problems with a Serviceguard package startup remain, a more
general debug mode can be activated by creating a "debug" file
touch ${SGCONF}/debug
All Serviceguard Extension for SAP on Linux packages on that cluster node will now be in debug mode. If
the file is created in the package directory ${SGCONF}/<SID>, it will only turn on the debug mode for
packages in that directory.
The debug mode allows a SGeSAP/LX package start up (mounts the appropriate storage volumes and
enables virtual IP addresses) without executing any of the SAP specific startups commands form within that
package. Service monitors will be started, but they will not report failures as long as the debug mode is
turned on.
With the debug mode enabled it then is possible to attempt manual startups of the database and/or SAP
software. All rules of manual troubleshooting of SAP instances now apply. As the storage volumes for this
package have know been mounted it is possible to access the SAP application work directories to check
trace files. After the error has been diagnosed the "debug" files has to be removed to resume normal
operation:
rm ${SGCONF}/debug
If the package still runs, all monitors will begin to work immediately and the package failover mechanism
is restored.
SAP Software Changes
During the configuration of SAP on Serviceguard Extension for SAP on Linux the SAP profiles (with kernel
<7.0) are modified to contain only virtual IP address instead of the initial physical IP addresses. This can be
checked using SAP transaction RZ10. In the DEFAULT.PFL these entries are altered:
SAPDBHOST= <relocatible_db_name>
rdisp/mshost= <relocatible_ci_name>
rdisp/vbname= <relocatible_ci_name>_<SID>_<INR>
rdisp/enqname= <relocatible_ci_name>_<SID>_<INR>
rdisp/btcname= <relocatible_ci_name>_<SID>_<INR>
rslg/collect_daemon/host = <relocatible_ci_name>
There are also two additional profile parameters SAPLOCALHOST and SAPLOCALHOSTFULL included as
part of the Instance Profile of the Central Instance. Anywhere SAP uses the local hostname internally, this
name is replaced by the relocatable values <relocatable_ci_name> or
<relocatable_ci_name>.domain.organization of these parameters. Make sure that they are
always defined and set to the correct value. This is vital for the system to function correctly.
120 Serviceguard Extension for SAP on Linux Cluster Administration