Managing Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64), February 2008

Step-by-Step Cluster Conversion
SAP Preparation
Chapter 3108
Creation of Replication Instance
The ASCS (ABAP) or SCS (JAVA) instance will be accompanied with an
[A]REP (ABAP or JAVA) instance that permanently keeps a mirror of the
ASCS internal state and memory. As a result, no information gets lost
due to the fact of failing SAP System Central Services, if the
Serviceguard Extension for SAP on Linux package that includes [A]SCS
fails over to the node that runs [A]REP during runtime.
RE070 Replicated Enqueue Conversion:
Create a new mountpoint:
su - <sid>adm
mkdir /usr/sap/<SID>/[A]REP<INSTNR>
RE080 Replicated Enqueue Conversion:
A volume group needs to be created for the [A]REP instance. The
physical device(s) should be created as LUN(s) on shared storage.
Storage connectivity is required from all nodes of the cluster that should
run the Replicated Enqueue. For the volume group, one logical volume
should get configured.
Mount the new logical volume to the mountpoint created in RE060.
RE090 Replicated Enqueue Conversion:
Create instance subdirectories in the mounted logical volume. They will
be switched between the cluster nodes later.
su - <sid>adm
cd /usr/sap/<SID>/[A]REP<INSTNR>
mkdir data log sec work
RE100 Replicated Enqueue Conversion:
Create instance profile and startup profile for the [A]REP Instance.
These profiles get created as <sid>adm in the NFS-shared
/sapmnt/<SID>/profile directory.
Even though this is a different instance, the instance number is identical
to the instance number of the [A]SCS. The virtual IP address used needs
to be different in any case.
Here is an example template for the instance profile
<SID>_[A]REP<INSTNR>_<[A]REPRELOC>: