Designing Disaster Recovery Clusters using Metroclusters and Continentalclusters, Reprinted October 2011 (5900-1881)

5 Building Disaster Recovery Serviceguard Solutions Using
Metrocluster with EMC SRDF
The EMC and Symmetrix Remote Data Facility (EMC SRDF) disk arrays allows configuration of
physical data replication solutions to provide disaster tolerance for Serviceguard clusters over long
distances. This chapter describes the EMC SRDF software and the additional files that integrate
the EMC with Serviceguard clusters. It then shows how to configure both metropolitan and
Continentalclusters solutions using EMC SRDF.
The topics discussed in this chapter are:
• Files for Integrating Serviceguard with EMC SRDF
• Overview of EMC and SRDF Concepts
• Preparing the Cluster for Data Replication
• Building a Metrocluster Solution with EMC SRDF
• Metrocluster with SRDF/Asynchronous Data Replication
• Metrocluster with SRDF/Asynchronous Multi-Session Consistency Data Replication
• Building Continentalclusters Solution with EMC SRDF
Metrocluster also defines a Site Aware Disaster Tolerant Architecture for complex workloads such
as Oracle RAC database, including Oracle 10gR2 RAC, Oracle 11gR1 RAC, Oracle 11gR2 RAC,
and SAP. This solution uses an additional software feature called the Site Controller Package to
provide disaster tolerance for workload databases. For more information on the site aware disaster
tolerant architecture, see “Overview of Site Aware Disaster Tolerant Architecture” (page 337).
Files for Integrating Serviceguard with EMC SRDF
Metrocluster is a set of executable programs, scripts and an environment file that work in an
Serviceguard cluster to automate failover to alternate nodes in the case of disaster in a metropolitan
cluster. The Metrocluster with EMC SRDF product contains the following files:
Table 21 Metrocluster with EMC SRDF Template Files
DescriptionName
The Metrocluster with EMC SRDF environmental file. This
file must be customized for the specific EMC Symmetrix,
/opt/cmcluster/toolkit/SGSRDF/srdf.env
and HP 9000 and, HP Integrity Servers host system
configuration. Copies of this file must be customized for
each separate Serviceguard package.
A directory containing sample convenience shell scripts
that must be edited before using. These shell scripts may
/opt/cmcluster/toolkit/SGSRDF/samples
help to automate some configuration tasks. These scripts
are contributed, and not supported.
The script that checks for a specific environment file in
the package directory and should not be edited.
/usr/sbin/DRCheckDiskStatus
The program that manages the SRDF device group that
is used by the package.
/usr/sbin/DRCheckSRDFDevGrp
Metrocluster with EMC SRDF has to be installed on all nodes that will run a Serviceguard package
that accesses data on an EMC Symmetrix where the data are replicated to a second Symmetrix
Files for Integrating Serviceguard with EMC SRDF 255