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

NOTE: For more detailed information on the sssu commands used in the sample input file, refer
to the sssu ReadMe file found at "/opt/cmcluster/toolkit/SGCAEVA/Samples/
Readme.sssu_sample_input
Follow the steps below when copying and editing the sample file:
1. Copy the sample file /opt/cmcluster/toolkit/SGCAEVA/Samples/
sssu_sample_input to the /etc/dtsconf/directory.
# cp /opt/cmcluster/toolkit/SGCAEVA \/Samples/sssu_sample_input
/etc/dtsconf/sssu_input
2. Customize the file sssu_input.
3. After you customize the sssu_input file, run the SSSU command as follows to set the
destination Vdisk to read-only mode
# /sbin/sssu “FILE <input_file>”
4. After changing the access mode of the destination Vdisk, it is necessary to run the ioscan
command and the insf command on remote clustered nodes to create the special device file
name for the destination Vdisk on remote EVA.
Cluster Configuration
For detailed information on Serviceguard cluster configuration, refer to the Managing Serviceguard
user’s guide. The following information pertains to cluster configuration in a EVA Continuous Access
environment. First create a Serviceguard cluster without specifying cluster-aware volume groups in
the cluster configuration ASCII file. This is necessary because the LUNs in the EVA storage units
are not read/write to all cluster nodes at configuration time. Only the LUNs configured as source
volumes are read/write on one cluster site. The remote site can see those LUNs with read-only
mode and therefore, the cmapplyconf command cannot succeed if volume groups are specified
in the file. Volume groups are created and made cluster aware in separate steps, shown in the
“Configuring Volume Groups” (page 223) of this chapter.
NOTE: If your ASCII file contains volume group definitions derived from the LUNs visible on the
source node, comment them out before running the cmapplyconfcommand.
Management Server/SMI-S and DR Groups Configuration
The Metrocluster Continuous Access EVA product provides two utility tools for users to provide
Metrocluster Continuous Access EVA software the information about the SMI-S EVA service running
on the Management Servers and DR groups that will be used in Metrocluster Continuous Access
EVA environment.
This section discusses the smispasswd and evadiscovery tools, including the description of the tools,
the tool operations, and the input file templates.The first utility, called smispasswd, is a Command
Line Interface (CLI) that provides functions for defining Management Server list and SMI-S username
and password pair. The second utility, called evadiscovery,is also a CLI that provides functions
for defining EVA storage cells and DR group information.
When Metrocluster Continuous Access EVA program requests a storage state, it sends a request
message to a local Management Server. For preparing the message, several data items need to
be available so that the Metrocluster Continuous Access EVA program knows which Management
Server it will communicate with. These data items include Management Server's hostname/IP
address, and SMI-S username/password. Before configuring and bringing up any Metrocluster
package, this is the first information that needs to be configured.
Metrocluster software communicates with the SMI-S service running on the Management Server,
which communicates with the EVA controller. When querying EVA storage states through the SMI-S,
the code first needs to find the internal device IDs by querying and searching for a list of devices
Preparing a Serviceguard Cluster for Metrocluster Continuous Access EVA 217