7.4.2 Planning for disaster

Because Server 1 and Server 2 are in separate data centers, Server 2 would be a good candidate for hosting a disaster recovery replica of the production environment served on Server 1. However, this DR environment does not necessarily need to be constantly running and consuming resources. The customer could carry out the following steps:

  • Create extra LPARs with definitions identical to those of the production environment.
  • Install and configure the WAS software on the extra LPARs.
  • Install and configure their applications with correct settings for the Disaster Recovery environment (for instance, JDBC connection strings should point at the DR version of databases).
  • Shut down the newly created LPARs, but leave them available to be restarted.

    At this point, the situation would be as depicted in Figure 7-5.

    Figure 7-5 Backup LPARs are created for the production environment but not running

    The only resource being consumed by the entire DR environment is disk. Server 2 is being actively used as a test and preproduction environment. In the event of a disaster, there is an understanding that these activities will be curtailed or limited.