Building Disaster Recovery Serviceguard Solutions Using Metrocluster with EMC SRDF

D Legacy packages
Configuring Serviceguard legacy packages for automatic disaster recovery
Before implementing the procedures to configure a legacy package it is necessary to do the
following:
• Configure your cluster hardware according to disaster recovery architecture guidelines. See
the Understanding and Designing Serviceguard Disaster Recovery Architectures user’s guide.
• Configure the Serviceguard cluster according to the procedures outlined in Managing
Serviceguard user’s guide.
• Create the EMC Solutions Enabler database, and build Symmetrix device groups, consistency
groups, and gatekeepers for each package. Export exclusive volume groups for each package
as described in “Preparing the Cluster for data replication” (page 12). This must be done on
each node that will potentially run the package.
• Install the Metrocluster with EMC SRDF product on all the nodes according to the instructions
in the Metrocluster with EMC SRDF Release Notes.
After these steps are completed, packages will be able to automatically fail over to an alternate
node in another data center and still have access to the required data.
This procedure must be repeated on all the cluster nodes for each Serviceguard application package
so the application can fail over to any of the nodes in the cluster. Customizations include setting
environment variables and supplying customer-defined run and halt commands, as appropriate.
The package control script must also be customized for the particular application software that it
will control.
For detailed instructions on how to start, halt, and move packages and their services between
nodes in a cluster, see the Managing Serviceguard user's guide.
For ease of troubleshooting, configure and test one package at a time.
1. Create a directory /etc/cmcluster/pkgname for each package.
# mkdir /etc/cmcluster/pkgname
2. Create a package configuration file.
# cd /etc/cmcluster/pkgname
# cmmakepkg -p pkgname.ascii
Customize the package configuration file as appropriate to your application. Be sure to include
the pathname of the control script (/etc/cmcluster/pkgname/pkgname.cntl) for the
RUN_SCRIPT and HALT_SCRIPT parameters.
3. The failover_policy parameter for a Metrocluster package can be set to
site_preferred. This value implies that during a Metrocluster package failover, while
selecting nodes from the list of the node_name entries, the Metrocluster package will first fail
over to the nodes that belong to the site of the node it last ran on, rather than the nodes that
belong to the other site. To use this policy the underlying cluster must be configured with sites
and each cluster nodes must be associated to a site.
NOTE: If using the EMS disk monitor as a package resource, do not use NO_TIMEOUT.
Otherwise, package shutdown will hang if there is no access from the host to the package
disks.
This product might increase package startup time by 5 minutes or more. Packages with many
disk devices will take longer to start up than those with fewer devices because of the time
required to get device status from the EMC Symmetrix disk array. Clusters with multiple
packages that use devices on the EMC Symmetrix disk array cause package startup time to
increase when more than one package is starting at the same time.
Configuring Serviceguard legacy packages for automatic disaster recovery 91