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Version: 2.9.0

Post Failover (Access Zone)

Introduction​

This guide will go through the different checks that should be executed once Failover is finished.

Post Failover Steps Unique to Access Zone Failover​

How to Verify that DNS Updates Were Completed Correctly​

  1. SSH into your Eyeglass IP address using a Terminal.

  2. Run the following command:

    nslookup

  3. Run the Server Command, replacing the X.X.X.X with the IP of the subnet service on the target Cluster.

    server X.X.X.X

  4. Enter a SmartConnect Zone name (format shown below)and press enter.

    Format: 
    <name>.<domain>

    Example:
    isi01-s0.example.com

  5. The expected response should be an IP address from the Target Cluster's IP Pool.

    tip

    If the received output is indeed from the Target Cluster IP Pool, then failover (as far as SmartConnect delegation to the target Cluster is concerned), was correct.

  6. Run the Server Command again, using the Production DNS server that has a modified CNAME.

  7. Repeat the tests above using a Production DNS Client IP address.

  8. Verify that the output returns an IP address from the Target Cluster IP Pool consistently.

How to Check for SPN Errors​

  • Review the Failover Log and verify that all the SPN steps were successful.
info

Failover logs are located under:

/opt/data/failover_logs/
  • If any SPN steps show as failed, manual recovery of the SPN will be required using the ADSIedit AD tool to perform delete and add of SmartConnect names or Alias names. This tool requires permissions to the computer account for the Cluster being edited.
info

The Failover Log contains all SPN SmartConnect names that were included in the failover.

Automated SMB Connection Switch to Target Cluster After Failover​

warning

This procedure can't be used if you disabled the SMB Protocol on the Cluster.

  1. Complete Failover as normal with Eyeglass DR Assistant.
  • Complete the following steps for each Access Zone IP Pool that was part of the Failover, and has SMB connections that should switch to the Target Cluster.
  1. View/edit the IP Pool. (To do this, on your PowerScale OneFS UI: click on Cluster Management, then External Network, and finally View/Edit the specific Pool.)
  2. Record the interfaces that are members of the pool. (this will be required to reconfigure the pool).
  3. Select all interfaces and click on Remove.
  4. Save the pool with no member interfaces.
  5. Once you've completed steps 1-4, all connected SMB clients will query DNS for the SmartConnect name and will re-mount and re-authenticate to the Target Cluster.
  6. View/edit the same IP Pool.
  7. Re-add the interfaces that were recorded in step 2.
  8. Save the Pool again.
  9. Repeat steps 1-7 for each IP Pool included in the Failover.
  10. Test data access to the Target Cluster to verify SMB clients have switched and can write data.

How to Manually Switch SMB Connection to Target Cluster After Failover​

To see this procedure, consult the How to Manually Switch SMB Connection to Target Cluster After Failover guide.

How to Refresh NFS Mounts After Failover​

NFS Mounts require an unmount and remount on the host (whichever it is that you're using).

  1. To unmount an export with open files, use the following option (force and lazy flag).

    umount -fl

  2. Remount the export, or, if configured in fstab, use the following command to remount any unmounted entries in the file.

    mount -a

Quota Updates​

After the update, there should be no quotas on the Source Cluster for the SyncIQ Policies in the Access Zone. On the Target Cluster, you should find all quotas for the SyncIQ Policies in the Access Zone.

SPN Updates​

After the update, there should be SPNs for all SmartConnect Zones, and SmartConnect Zone Aliases related to the subnet pools associated with the access zone that was failed over.

SmartConnect Zone Updates​

Post Failover, the following should be true regarding the SmartConnect Zones and Aliases related to the subnet pools associated with the Access Zone that was failed over.

  1. Eyeglass created SmartConnect one alias on Target Cluster, with the same name as the SmartConnect Zone on the Source Cluster partner IP Pool.
  2. Eyeglass updated the Source Cluster SmartConnect Zone name with the prefix "igls-original-".
  3. The Alias for the Target SmartConnect Zone is removed from the Source Cluster.
  4. After Failover is completed, DNS Admin or Post Failover scripting updates DNS entry for the SmartConnect Zone name must use the SmartConnect Service IP address from the Target Cluster.

SyncIQ Policy Updates​

To see this procedure, please consult the How to Verify SyncIQ Policy Updates guide.