Managing Serviceguard Extension for SAP Version B.05.10, December 2012

Prior to any instance startup attempts the SGeSAP tries to free up unused or unimportant resources
to make the startup more likely to succeed. A database package only frees up database related
resources, a SAP Instance package only removes IPCs belonging to SAP administrators.
The following list summarizes how the behavior of SGeSAP is affected with different settings of the
cleanup_policy parameter:
• lazy—no action, no cleanup of resources.
• normal—removes orphaned resources as reported by SAP tools for the SAP system that is
specified in sap_system. An obsolete ORACLE SGA is also removed if a database crash
occurred.
• strict—uses HP-UX commands to free up system resources that belong to any SAP Instance
of any SAP system on the host if the Instance is to be started soon.
NOTE: Do not use the strict policy unless it is required. Be aware that the strict option can crash
running instances of different SAP systems on the backup host. Use this value only if you have a
productive system that is much more important than any other SAP system you have. In this case,
a switchover of the productive system is more robust, but additional SAP systems will crash.
You can also use strict policy, if your SAP system is the only one running at the site and you are
low on memory. Strict policy frees up more of its own shared memory segments than the normal
policy does.
Optional Step: OS423
It is possible to influence the system cleanup behavior of SGeSAP.
Many SGeSAP package activities depend on system resources that are provided via mechanisms
that are not directly handled by the package. If these resources are not available, a package
operation could fail. Sometimes the resources are just temporarily unavailable and the package
activity would succeed if delayed long enough. To allow that kind of synchronization, SGeSAP
enters loops that poll missing resources regularly and delays or retries activities that depend on
these resources. The package activity continues after the resource becomes available again or
fails after a maximum of retry_count attempts to successfully finish the activity.
The default for the parameter is set to 5. It can be raised on demand, if the package logs indicate
racing conditions with timing issues.
Optional Step: OS424
It is possible to influence the startup and monitoring methods for SAP Netweaver instances.
The package parameter sapcontrol_usage allows you to specify whether the SAP Netweaver 7
sapcontrol interface and the SAP startup agent framework is required to startup, shutdown, and
monitor the SAP software components.
The recommended value preferred is that SGeSAP tries to use sapcontrol methods to start, stop,
and monitor the state of an instance. But alternate monitoring methods are used if the startup agent
framework is not functional. This includes either legacy monitoring tools as provided by SAP or
operating environment monitoring or both.
Similarly, in case the startup framework fails to handle startup or shutdowns, other available
methods to start or stop the software are used as fallback strategy.
In case the startup framework is available, but not recommended to use, set the parameter to
disabled to avoid the usage.
In case all Netweaver instance start, stop, and monitor functions are recommended to rely only on
SAP's startup framework, set the parameter to exclusive.
Subsection for the Oracle database component: OR425
Parameters that can be set to handle an Oracle single-instance database as part of a package with
the sgesap/dbinstance or sgesap/oracledb module.
82 Step-by-Step Cluster Conversion