Managing Serviceguard Extension for SAP, December 2007

Step-by-Step Cluster Conversion
SAP Preparation
Chapter 3100
Splitting an ABAP Central Instance
The SPOFs of the DVEBMGS<INSTNR> instance will be isolated in a new
instance called ABAP System Central Services Instance ASCS<INSTNR>.
This instance will replace DVEBMGS<INSTNR> for the ci package type. The
remaining parts of the Central Instance can then be configured as Dialog
Instance D<INSTNR_2>. The ASCS Instance should then only be started
and stopped with the cluster package startup and halt commands
instead of using manual shell operations.
NOTE The Dialog Instance D<INSTNR_2>that results from the conversion also
represents one or more Single Points of Failure for many scenarios. In
these cases, D<INSTNR_2> should also be clustered with SGeSAP. It is
not even unusual to combine ASCS<INSTNR> and D<INSTNR_2> in a
single SGeSAP package. It makes sense, even though the resulting
package contains the same components like a traditional package for
DVEBMGS<INSTNR> would. Seamless failover with Replicated Enqueue
can not be achieved without splitting up DVEBMGS<INSTNR> into two
instances.
Logon as root to the server on which the Central Instance
DVEBMGS<INSTNR> was installed.
RE010 Replicated Enqueue Conversion:
Create a new mountpoint:
su - <sid>adm
mkdir /usr/sap/<SID>/ASCS<INSTNR>