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Version: 2.9.2

What is Policy Failover?

Introduction​

Policy Failover is a tool designed to assess and manage disaster recovery readiness for data configurations. It provides a detailed overview of replication job statuses, enabling quick identification and resolution of issues. This ensures that each SyncIQ policy is prepared for a successful failover. The tool offers guidance on reviewing failover logs, identifying failed steps, and executing recovery processes, helping to minimize downtime and maintain data integrity during disaster recovery scenarios​​.

Which factors are involved?​

When setting up Policy Failover in Superna Eyeglass, important factors need to be addressed to ensure a smooth transition:

  • Cluster Compatibility: Ensure that the PowerScale OneFS clusters involved are compatible with Superna Eyeglass to avoid configuration errors.

  • SyncIQ Policy Status: The SyncIQ Policy and corresponding replication job must be enabled to allow the failover process to proceed.

  • Network Setup: The target cluster must be accessible over the network, with all necessary ports open.

  • SPN Updates: Manually update Service Principal Names (SPN) for direct mount shares to ensure proper authentication post-failover.

  • Replication Topology: Avoid using the same share names for different SyncIQ policies on the source and target clusters to prevent failover issues.

  • SmartConnect Zones: Use dedicated SmartConnect Zones for each SyncIQ Policy to simplify network updates after a failover.

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For more details, please refer to the Policy Failover Configuration Prerequisites.

How is Policy Failover executed?​

Policy Failover is a structured process executed through Eyeglass and involves the following key steps:

  1. Failover Initiation: The process begins by initiating the failover from Eyeglass.

  2. Final SyncIQ Run: Before the transition, the SyncIQ policy runs one last time on the source cluster to ensure all data is fully synchronized.

  3. Making the Target Path Writable: The SyncIQ policy on the target cluster is updated to make the target path writable.

  4. Resync Preparation: Eyeglass prepares a mirror SyncIQ policy on the target cluster and runs it. This resync process captures any remaining data changes, ensuring the target cluster has the most up-to-date data.

  5. Quota Management: During this step, quotas on the source cluster are deleted and recreated on the target cluster.

  6. Post-Failover Manual Steps: After the failover, some manual steps are required. SMB shares and NFS exports/aliases must be remounted on a SmartConnect Zone Name from the target cluster.

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The process is largely automated by Eyeglass, but careful attention to the manual steps, particularly around SPN management and SmartConnect configuration, is necessary for a successful failover.

What are the results of Policy Failover?​

The successful execution of a Policy Failover leads to several key outcomes that ensure business continuity and data integrity:

  • Seamless Data Access: After the failover, clients can continue to access their data from the target cluster without interruption. The remounting of SMB shares and NFS exports ensures that all connections are correctly redirected to the new cluster.

  • Data Consistency: The final SyncIQ run before failover ensures that all data is fully synchronized between the source and target clusters.

  • Maintained Security and Authentication: Proper management of Service Principal Names (SPNs) and DNS records during the failover process ensures that all authentication protocols remain intact.

  • Optimized Resource Allocation: By moving active data operations to the target cluster, the load is balanced across the infrastructure, optimizing resource utilization.

  • Restored Quotas: Quotas are reestablished on the target cluster, maintaining the same data access controls that were in place on the source cluster.

  • Granular Control: The process allows for granular control over which SyncIQ Policies are failed over, providing flexibility in disaster recovery scenarios.

  • Manual Adjustments: While much of the failover process is automated, the manual steps required, such as SmartConnect and SPN management.