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Version: 4.0.0

Storage Failover Steps

Introduction​

The storage layer failover process is a critical part of disaster recovery (DR). A complete DR plan should also address application shutdown and restart procedures to ensure seamless failover. The storage layer provides the foundation for all higher-level failover processes, and Eyeglass streamlines this step while enabling error detection during failover.

For complex or application-layer failover scenarios, Superna Professional Services offers support through Proof of Concept (POC) engagements, recommendations, and assessments. Examples include:

  • VMware SRM with externally mounted storage for virtual machines.
  • Oracle RAC Data Guard with file system dependencies for applications.

After identifying the Failover Mode suitable for your environment, the next section describes the high-level steps for each mode.

Failover Modes and High-Level Steps​

Ordered Steps for Non-DFS and DFS Mode​

This step-by-step process details failover actions for SyncIQ Policy or Microsoft DFS Mode. Each item specifies its purpose, describes the action performed, and explains how the action is initiated based on the selected failover mode.

  1. Ensure There Is No Live Access to Data (Source)

    Verify that no active operations are accessing the data to prevent inconsistencies during failover.
    Perform a manual check for open files. If open files are found, determine whether to wait for their closure or proceed with the failover.

    • How Action Is Initiated:
      • SyncIQ Mode: Manual
      • DFS Mode: Manual
    note

    The DR Assistant Data Integrity failover option (version 2.0 or later) blocks IO to SMB shares before failover starts.

    tip

    Disable SMB and NFS protocols on the source cluster. This is a cluster-wide operation designed to eliminate data loss.

    1. Enable Data Integrity Failover (SMB Only)
      Applies the "Deny Everyone" setting to SMB shares before the failover process begins.

      • How Action Is Initiated:
      • SyncIQ Mode: Automated by Eyeglass
      • DFS Mode: Automated by Eyeglass

    2. Cache Schedule for SyncIQ Policies Being Failed Over
      Retrieves the schedule for SyncIQ policies being failed over on OneFS and sets policies to manual to ensure they do not run again during failover.

      • How Action Is Initiated:
      • SyncIQ Mode: Automated by Eyeglass
      • DFS Mode: Automated by Eyeglass

  2. Begin Failover With DR Assistant (Eyeglass)
    Initiates the failover process from Eyeglass.

    • How Action Is Initiated:
      • SyncIQ Mode: Manual or Eyeglass REST API
      • DFS Mode: Manual or Eyeglass REST API

  3. Validation of Failover Job (Eyeglass)
    Verifies all warnings before submitting the failover job to ensure successful execution.

    • How Action Is Initiated:

      • SyncIQ Mode: Automated by Eyeglass

      • DFS Mode: Automated by Eyeglass

    1. Validation - Block on Warning Enabled
      Prevents the failover process from continuing if warnings, such as quota scan requirements, are detected.

      • How Action Is Initiated:
        • SyncIQ Mode: Automated by Eyeglass
        • DFS Mode: Automated by Eyeglass

    2. Set Eyeglass Config Jobs to User-Disabled
      Sets Eyeglass configuration jobs to a user-disabled state to prevent failed steps from running. Jobs can only run if the user re-enables them post-failover.

      • How Action Is Initiated:

        • SyncIQ Mode: Automated by Eyeglass
        • DFS Mode: Automated by Eyeglass

  4. Synchronize Data (Run SyncIQ Policies)
    Runs all OneFS SyncIQ policy jobs related to the Access Zone being failed over.

    • How Action Is Initiated:
      • SyncIQ Mode: Automated by Eyeglass
      • DFS Mode: Automated by Eyeglass

  5. Synchronize Configuration
    Executes Eyeglass configuration replication, including shares, export aliases, snapshot schedules, and dedupe paths.

    • How Action Is Initiated:
      • SyncIQ Mode: Automated by Eyeglass (configuration exists on source and target)
      • DFS Mode: Automated by Eyeglass

  6. Renaming Shares for DFS Mode to Redirect DFS Clients For DFS failover, shares are renamed on the source and target clusters to redirect clients with dual DFS target paths to the target cluster.

    • How Action Is Initiated:

      • SyncIQ Mode: Not Applicable
      • DFS Mode: Automated by Eyeglass
      info

      DFS Mode: Special handling renames shares on the source and target so only one DFS target UNC is reachable and active for DFS clients to switch over.

  7. Provide Write Access to Data on Target Allow writes to SyncIQ policies related to failover.

    • How Action Is Initiated:
      • SyncIQ Mode: Automated by Eyeglass
      • DFS Mode: Automated by Eyeglass

  8. Disable SyncIQ on Source and Activate on Target

    Prepare for failover by creating a mirror policy on the target. Disable the source cluster policy and enable the target cluster policy on OneFS.

    • How Action Is Initiated:
      • SyncIQ Mode: Automated by Eyeglass
      • DFS Mode: Automated by Eyeglass

  9. Reset SyncIQ Schedule on Target Mirror Policy

    Apply the schedule to the target mirror policy using the schedule retrieved from Step 1.

    • How Action Is Initiated:
      • SyncIQ Mode: Automated by Eyeglass
      • DFS Mode: Automated by Eyeglass

  10. Failover Quotas (Optional) Eyeglass DR Assistant automatically fails over quotas by running quota jobs related to the SyncIQ policies being failed over.

    • How Action Is Initiated:

      • SyncIQ Mode: Automated by Eyeglass

        info

        Quotas are deleted on the source cluster and created on the target cluster.

      • DFS Mode: Automated by Eyeglass

        info

        Quotas are deleted on the source cluster and created on the target cluster so that post-failover quotas are applied.

  11. Remove Quotas on Directories That Are Targets of SyncIQ Eyeglass deletes all quotas on the source cluster for the specified policies.

    • How Action Is Initiated:

      • SyncIQ Mode: Automated by Eyeglass

      • DFS Mode: Automated by Eyeglass

    1. Run Mirror Policy Executes the mirror policy to resync data in the reference direction.

      • How Action Is Initiated:
        • SyncIQ Mode: Automated by Eyeglass
        • DFS Mode: Automated by Eyeglass

    2. Set Eyeglass Config Jobs to Enabled
      Enables configuration synchronization only if the Resync Prep step completes successfully for the policy.

      • How Action Is Initiated:
        • SyncIQ Mode: Automated by Eyeglass
        • DFS Mode: Automated by Eyeglass

  12. Change SmartConnect Zone on Source
    Rename SmartConnect zones and aliases on the source cluster to prevent names from being resolved by clients.

    • How Action Is Initiated:
      • SyncIQ Mode: Manual
      • DFS Mode: Not Required (source and destination clusters can use existing SmartConnect zones)

  13. Avoid SPN Collision
    Sync SPNs in all Active Directory (AD) providers to match the current SmartConnect zone names and aliases on the source cluster.

    • How Action Is Initiated:
      • SyncIQ Mode: Manual (deletes SmartConnect SPN from the source cluster machine account)
      • DFS Mode: Not Applicable (DFS SPNs are not changed during failover)

  14. Move SmartConnect Zone to Target
    Add source SmartConnect zones as aliases on the target cluster.

    • How Action Is Initiated:
      • SyncIQ Mode: Manual
      • DFS Mode: Not Required (source and destination clusters can use existing SmartConnect zones)

  15. Create SPNs for Kerberos Authentication on Target for SMB Shares
    Sync SPNs in all Active Directory (AD) providers to match current SmartConnect zone names and aliases on the target cluster.

    • How Action Is Initiated:
      • SyncIQ Mode: Manual (adds new SmartConnect alias SPNs to the target cluster machine account)
      • DFS Mode: Not Applicable (DFS SPNs are not changed or registered to cluster machine accounts)

  16. Repoint DNS to the Target Cluster IP Address
    Update DNS delegations for all SmartConnect zones that are members of the access zone.

    • How Action Is Initiated:
      • SyncIQ Mode: Manual
      • DFS Mode: Not Applicable (no updates are needed as DFS resolution has not changed in DNS, only the target UNC with an active share)

  17. Refresh Session to Pick Up DNS Change
    Remount the SMB/NFS shares.

    • How Action Is Initiated:
      • SyncIQ Mode: Manual on clients
      • DFS Mode: Automatic (Windows 7 or later with DFS support)

Ordered Steps for Access Zone or IP Pool Failover​

This section outlines the step-by-step process for failover involving Access Zones or IP Pools. Each step describes the action performed, its purpose (if necessary), and how the action is initiated. Let me know the details for the first step, and I’ll format it according to the guidelines.

  1. Ensure That There Is No Live Access to Data (Source)
    Perform a manual check for open files. If open files are found, decide whether to wait for them to close or proceed with the failover.

    tip

    Disable SMB and NFS protocols on the source cluster before failover. This is a cluster-wide operation required to prevent data loss.

    • How Action Is Initiated:

      • Access Zone: Manual

    1. Enable Data Integrity Failover (SMB Only)

      Applies the "Deny Everyone" setting to SMB shares before the failover process begins.

      • How Action Is Initiated:
        • Access Zone: Automated by Eyeglass

    2. Cache Schedule for SyncIQ Policies

      Retrieves the schedule associated with SyncIQ policies being failed over on OneFS. Sets policies to manual to ensure they do not run again during failover.

      • How Action Is Initiated:
        • Access Zone: Automated by Eyeglass

  2. Begin Failover With DR Assistant (Eyeglass)
    Initiate the failover process from Eyeglass.

    • How Action Is Initiated:
      • Access Zone: Manual or Eyeglass REST API

  3. Validation of Failover Job (Eyeglass)
    Verify all warnings before submitting the failover job.

    • How Action Is Initiated:

      • Access Zone: Automated by Eyeglass

    1. Validation - Block on Warning Enabled
      Prevents the failover process from continuing if warnings are detected, such as quota scan requirements.

      • How Action Is Initiated:
        • Access Zone: Automated by Eyeglass

    2. Set Eyeglass Config Jobs to User-Disabled
      Configures Eyeglass jobs to a user-disabled state to prevent failed steps from running unless re-enabled manually after the failover.

      • How Action Is Initiated:
        • Access Zone: Automated by Eyeglass

  4. Synchronize Data (Run SyncIQ Policies)
    Run all OneFS SyncIQ policy jobs related to the Access Zone being failed over.

    • How Action Is Initiated:

      • Access Zone: Automated by Eyeglass

        info

        All policies in the Access Zone.

  5. Synchronize Configuration
    Run Eyeglass configuration replication, including shares, export aliases, snapshot schedules, and dedupe paths.

    • How Action Is Initiated:

      • Access Zone: Automated by Eyeglass

        info

        Based on matching Access Zone base path.

  6. note

    It is possible to integrate DFS-protected data inside an Access Zone failover to protect shares, exports, and DFS data as part of the Access Zone failover process.

    If DFS is configured, redirect rename steps would be executed at this point.

  7. Change SmartConnect Zone on Source
    Rename SmartConnect zones and aliases on the source cluster to prevent client resolution. Dual delegation eliminates the need for DNS updates.

    • How Action Is Initiated:

      • Access Zone: Automated by Eyeglass

        info

        Based on matching Access Zone base path.

  8. Avoid SPN Collision
    Sync SPNs in all Active Directory (AD) providers to match current SmartConnect zone names and aliases. The proxy is configured through the target cluster.

    • How Action Is Initiated:

      • Access Zone: Automated by Eyeglass

        info

        AD delegation must be completed as per install documentation.

  9. Move SmartConnect Zone to Target Add source SmartConnect zones and aliases on the target cluster.

    • How Action Is Initiated:
      • Access Zone: Automated by Eyeglass

  10. Update SPN to Allow Authentication Against Target Sync SPNs in all Active Directory (AD) providers to match current SmartConnect zone names and aliases. Proxy configuration is handled through the target cluster.

    • How Action Is Initiated:
      • Access Zone: Automated by Eyeglass

  11. Repoint DNS to the Target Cluster IP Address
    Perform DNS dual delegation for all SmartConnect zones that are members of the Access Zone.

  12. Remove Quotas on Directories That Are Targets of SyncIQ Eyeglass deletes all quotas on the source cluster for the specified policies.

    • How Action Is Initiated:

      • SyncIQ Mode: Automated by Eyeglass

      • DFS Mode: Automated by Eyeglass

    1. Run Mirror Policy
      Execute the mirror policy to resync data in the reference direction.

      • How Action Is Initiated:
      • Access Zone: Automated by Eyeglass

    2. Set Eyeglass Config Jobs to Enabled
      Enables configuration synchronization only if the Resync Prep step completes successfully for the policy.

      • How Action Is Initiated:
      • Access Zone: Automated by Eyeglass

  13. Disable SyncIQ on Source and Make Active on Target

    Perform the resync prep SyncIQ policy step to failover. This creates a mirror policy on the target, disables the source cluster policy, and enables the target cluster policy in OneFS.

    • How Action Is Initiated:
      • Access Zone: Automated by Eyeglass

  14. Set Proper SyncIQ Schedule on Target

    Set the schedule on the mirror policy (target) using the schedule retrieved from step 6 in OneFS for the policies related to the failover.

    • How Action Is Initiated:
      • Access Zone: Automated by Eyeglass

  15. Synchronize Quotas

    Run Eyeglass quota jobs related to the SyncIQ policy or Access Zone being failed over.

    • How Action Is Initiated:
      • Access Zone: Automated by Eyeglass

  16. Repoint DNS to the Target Cluster IP Address

    Dual delegation with Eyeglass avoids DNS steps during failover for all SmartConnect zones that are failed over.

  17. Refresh Session to Pick Up DNS Change

    Remount the SMB/NFS shares or remount exports if data integrity remount is not required for SMB.

Additional Information​

  1. Initiates Eyeglass Configuration Replication task for all Eyeglass jobs.


  2. SyncIQ does NOT modify the ACL (Access control settings on the file system); it locks the file system.


  3. A system.xml change is required to enable parallel step mode.

    note

    All policy steps are attempted. On failure, the failover job will continue to attempt all steps and skip downstream steps per policy if the previous SyncIQ step failed.

See Also​