Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Building a Metropolitan Cluster Using MetroCluster/SRDF
Overview of MetroCluster/SRDF
Chapter 4124
Overview of MetroCluster/SRDF
MetroCluster is a set of scripts and an environment file that work in an
MC/ServiceGuard cluster to automate failover to alternate nodes in the
case of disaster in a metropolitan cluster. The MetroCluster/SRDF
product contains the following files.
MetroCluster/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 using the SRDF facility.
In the event of node failure, the integration of MetroCluster/SRDF with
the package will allow the application to fail over in the following ways:
• among local host systems that are attached to the same EMC
Symmetrix.
• between one system that is attached locally to its EMC Symmetrix
and another “remote” host that is attached locally to the other EMC
Symmetrix.
Table 4-1 MetroCluster/SRDF Template Files
Name Description
/opt/cmcluster/toolki
t/SGSRDF/srdf.env
The MetroCluster/SRDF environmental file. This file
must be customized for the specific EMC Symmetrix
and HP 9000 host system configuration. Copies of this
file must be customized for each separate
MC/ServiceGuard package.
/opt/cmcluster/toolkit/SGS
RDF/samples
A directory containing sample convenience shell
scripts that must be edited before using. These shell
scripts may help to automate some configuration tasks.
These scripts are contributed, and not supported.
/usr/sbin/DRCheckDiskSt
atus
The script that checks for a specific environment file in
the package directory and should not be edited.
/usr/sbin/DRCheckSRDF
DevGrp
The script that checks the status of the SRDF device
group that is used by the package and should not be
edited.