Managing HP Serviceguard Extension for SAP for Linux (May 2013)

Configuration restrictions
The following are the configuration restrictions:
• The sgesap/sapinstance module must not be used for Diagnostic Agents.
• It is not allowed to specify a single SGeSAP package with two database instances in it.
• It is not allowed to specify a single SGeSAP package with a Central Service Instance [A]SCS
and its corresponding Replication Instance ERS.
• The Diagnostic Agent instances are not mandatory for SAP line-of-business processes, but they
become installed on the relocatable IP address of the corresponding instance. The instances
must failover with the relocatable IP address. You must specify the sgesap/sapextinstance
module. Diagnostic Agent start and stop issues during failover are not critical for the overall
success of the failover of the package.
• It is not a requirement, but it can help to reduce the complexity of a cluster setup, if SCS and
ASCS are combined in a single package. If this setup is selected, the failure of one of the two
instances also causes the failover of the other healthy instance. This might be tolerable in cases
in which SAP replication instances are configured.
• The sgesap/sapinstance packages can identify the state of their corresponding
sgesap/dbinstance package in the same cluster without the requirement of explicitly
configuring Serviceguard package dependencies. The information is for example used to
delay SAP instance package startups while the database is starting in a separate package,
but not yet ready to accept connections.
Example 1: Robust failover using the one package concept
In a one-package configuration, the database, NFS, and SAP SPOFs run on the same node at all
times and are configured in one SGeSAP package. Other nodes in the Serviceguard cluster function
as failover nodes for the primary node on which the system runs during normal operation.
Configuration restrictions 9