Policy Failover Configuration Prerequisites

Introduction

Here you will learn the essential prerequisites for configuring and executing a successful SyncIQ Policy failover with Eyeglass. It covers the necessary cluster versions, SyncIQ policies, network setup, and other key recommendations to ensure a seamless and error-free failover process. Adhering to these guidelines is critical for avoiding data loss, managing configuration errors, and automating manual steps required post-failover.

Policy Failover Requirement

To utilize Eyeglass Policy Failover, the following conditions must be met:

Cluster Version

Clusters involved in SyncIQ Policy Failover must operate on a PowerScale OneFS Cluster version that supports this feature. To confirm compatibility, refer to the Release Compatibility.

SyncIQ Policy

For a SyncIQ Policy failover with Eyeglass, it is required that the Eyeglass Configuration Replication Job for that SyncIQ Policy is in the Enabled state.

note

If the SyncIQ Policy is disabled in PowerScale OneFS or the corresponding Eyeglass Configuration Replication Job is disabled in Eyeglass, the SyncIQ Policy failover will be blocked.

Failover Target Cluster Requirements

For a SyncIQ Policy failover with Eyeglass, the PowerScale OneFS Cluster that is the target of the failover must be IP reachable by Eyeglass with the required ports open.

Eyeglass Quota Job Requirements

For a SyncIQ Policy failover with Eyeglass, there are no specific state requirements for the Eyeglass Quota Job. Quotas will be failed over regardless of whether the Eyeglass Quota Job is in the Enabled or Disabled state.

Service Principal Name Update Requirements

DFS mode and Access Zone failover manage SPN updates automatically. Manual intervention is only required when a SyncIQ policy failover includes direct mount shares.

Eyeglass allows SyncIQ policy failover, but the storage administrator must selectively update SPN values on the source and destination clusters. This ensures that datasets remaining on the source cluster continue to process SPN authentications via Kerberos using the source cluster machine account. Administrators must manually delete and add SPNs on the target cluster, as the PowerScale OneFS cluster cannot determine which SPNs and SmartConnect Zones are associated with the SMB Shares.

Steps:

1. Delete the SPNs from the source cluster.
2. Add the SPNs to the target cluster.

This must be done manually by reviewing the SmartConnect Zones required for the failover.

Unsupported Data Replication Topology

Replication topologies where shares or NFS aliases have the same name on both clusters but are protected by different SyncIQ policies are not supported. This configuration leads to the following issues:

• Path Overwriting: Configuration replication will overwrite the share/alias path on one cluster because the share or alias cannot be distinguished across clusters.
• Failover Failure: During failover, the system will attempt to apply two SyncIQ policies on the same cluster with identical source paths, resulting in failure.
• Invalid Disaster Recovery (DR) Configuration: This setup leads to duplicate shares pointing to different data, which is an invalid DR configuration.
  info

  This configuration will cause failover to be unsuccessful, with or without Superna Eyeglass.

Recommendations for Eyeglass Assisted SyncIQ Policy Failover

Bellow you can see important recommendations to ensure that all automated SyncIQ Policy failover steps can be completed. In some cases, if the condition is not met, it will result in an error.

recommendations

• Errors will not block Eyeglass Assisted SyncIQ Failover from starting.
  • If the recommendations are not followed, it may result in an error during failover, causing the failover to not complete.
  • Potential data loss may be incurred depending on the step that failed.
  • Post failover may require additional manual steps to complete the failover with application hosts.
  • Post failover scripting should be used to automate custom failover requirements per policy.

Shares / Exports / NFS Alias Recommendations

• Eyeglass Configuration Replication Jobs for the SyncIQ Policies being failed over should have been completed (not in a Pending state) without error before the failover is started.

Impact

• Failover will be interrupted if the configuration synchronization encounters any errors during the process.
• Any missing or unsynced share / export / NFS alias information will block client access to data on the Target cluster. These configuration items will need to be corrected manually on the Target Cluster.

SyncIQ Policy Recommendations

• The SyncIQ Job in PowerScale OneFS should be completed without errors and display a green status.

Impact

Failover will be interrupted if any errors occur during the failover process. Data loss may occur due to unreplicated data.

• PowerScale OneFS does not support SyncIQ Policies with exclude (or include) settings for failover.

Impact

This configuration is not supported for failback, which may result in additional manual intervention.

• PowerScale OneFS best practices recommend that SyncIQ Policies use the Restrict Source Nodes option, which requires an IP created with the target SmartConnect zone.

Impact

The subnet pool used for data replication is not controlled, meaning that all nodes in the cluster can replicate data from all IP pools. This complicates bandwidth management and requires all nodes to have WAN access.

SmartConnect Recommendations

It is recommended to have a dedicated SmartConnect Zone or SmartConnect Zone Alias for data access per SyncIQ Policy, rather than sharing a SmartConnect Zone or Alias between policies. This allows clients to continue using the same SmartConnect Zone for data access post-failover and simplifies the associated networking updates.

Impact

• Ensures seamless data access for clients post-failover.
• Simplifies networking updates by reducing the complexity of reconfiguring shared SmartConnect Zones.

Next Steps

Policy Failover Configuration Procedures