Building Disaster Recovery Serviceguard Solutions Using Metrocluster with 3PAR Remote Copy

NOTE: The maximum number of SSH connections to a 3PAR storage array is 16.
Overview of a Metrocluster configuration
A Metrocluster is configured with the nodes at Site A and Site B. When Site A and Site B form a
Metrocluster, a third location is required where Quorum Server or arbitrator nodes must be
configured. There is a 3PAR storage system at each site and they are connected to each other
through Remote Copy links.
An application is deployed in a Metrocluster by configuring it at both the sites. The sites are referred
either as DC1 or DC2 for an application, based on their role. Typically, the application runs on
DC1 site which is the primary site. If there is a disaster in DC1 site, the application automatically
fails over to the recovery site referred as DC2 site.
NOTE: DC1 and DC2 are application-specific roles of a site.
For each application, either synchronous or asynchronous periodic mode replication is configured
to replicate data between the two sites using Remote Copy volume group. In a typical configuration,
more than one application is configured to run in a Metrocluster. Depending on the application
distribution in a Metrocluster environment, some applications can have Site A as its DC1 while
some other applications can have Site B as its DC1.
Figure 1 Sample configuration of Metrocluster with 3PAR Remote Copy
Quorum Server
Switch Switch
Node 1 Node 2 Node 3 Node 4
Site A Site B
3PAR Array 3PAR Array
Synchronous / Periodic Asynchronous
DC1 for App A
DC2 for App B
DC1 for App B
DC2 for App A
A B
3PAR
Metrocluster
3PAR
Figure 1 depicts an example of two applications distributed in a Metrocluster with 3PAR Remote
Copy environment balancing the server and replication load. In this example, Site A is the primary
site or DC1 for application A, and recovery site or DC2 for application B. Site B is the primary
site or DC1 for application B, and recovery site or DC2 for application A.
10 Introduction