Hitachi Disaster Recovery Solution simplifies the deployment and maintenance of 2-node and 4-node stretched clusters distributed across two geographically separate sites and storage arrays. The arrays are synchronized using Global Active Directory (GAD) technology, which ensures that data is mirrored in real time between the sites. Because server memory and stored data are mirrored between the two arrays, GAD provides a zero Recovery Point Objective (RPO) if a single component or complete site fails.
The Hitachi Disaster Recovery Solution also includes a quorum disk to monitor the GAD pair volumes. The quorum disk acts as a heartbeat for the GAD pair, with both storage systems accessing the quorum to check on each other. The quorum helps to avoid a split-brain scenario where multiple nodes are writing to the same part of the data simultaneously, which could cause data corruption and loss.
Disaster Recovery Solution is installed and accessed from the Hitachi Virtual Storage Platform One File (VSP One File) management software version 1.6 or later to set up a high-availability and disaster recovery solution for supported block storage systems.
The following figure shows the component in the Disaster Recovery Solution environment:
For an in-depth description of the design, configuration, and components in the Disaster Recovery Solution environment, including site configuration and networking examples, see the Hitachi Disaster Recovery Solution System Architecture Guide.