1920: Global and Metro Mirror persistent error.

Explanation

This error might be caused by a problem on the primary cluster, a problem on the secondary cluster, or a problem on the inter-cluster link. The problem might be a failure of a component, a component becoming unavailable or having reduced performance because of a service action or it might be that the performance of a component has dropped to a level where the Metro Mirror or Global Mirror relationship cannot be maintained. Alternatively the error might be caused by a change in the performance requirements of the applications using Metro Mirror or Global Mirror.

This error is reported on the primary cluster when the copy relationship has not progressed sufficiently over a period of time. Therefore, if the relationship is restarted before all of the problems are fixed, the error might be reported again when the time period next expires (the default period is five minutes).

This error might also be reported because the primary cluster has encountered read errors.

You might need to refer to the Copy Services features information in the software installation and configuration documentation while diagnosing this error.

User Response

  1. If the 1920 error has occurred previously on Metro Mirror or Global Mirror between the same clusters and all the following actions have been attempted, contact your product support center to resolve the problem.
  2. On both clusters, check the partner fc port mask to ensure that there is sufficient connectivity. If the partner fc port mask was changed recently, ensure the mask is correct.
  3. On the primary cluster reporting the error, correct any higher priority errors.
  4. On the secondary cluster, review the maintenance logs to determine if the cluster was operating with reduced capability at the time the error was reported. The reduced capability might be because of a software upgrade, hardware maintenance to a 2145 node, maintenance to a backend disk system or maintenance to the SAN.
  5. On the secondary 2145 cluster, correct any errors that are not fixed.
  6. On the intercluster link, review the logs of each link component for any incidents that would cause reduced capability at the time of the error. Ensure the problems are fixed.
  7. If a reason for the error has been found and corrected, go to Action 11.
  8. On the primary cluster reporting the error, examine the 2145 statistics using a SAN productivity monitoring tool and confirm that all the Metro Mirror and Global Mirror requirements described in the planning documentation are met. Ensure that any changes to the applications using Metro Mirror or Global Mirror have been taken into account. Resolve any issues.
  9. On the secondary cluster, examine the 2145 statistics using a SAN productivity monitoring tool and confirm that all the Metro Mirror and Global Mirror requirements described in the software installation and configuration documentation are met. Resolve any issues.
  10. On the intercluster link, examine the performance of each component using an appropriate SAN productivity monitoring tool to ensure that they are operating as expected. Resolve any issues.
  11. Mark the error as "fixed" and restart the Metro Mirror or Global Mirror relationship.

When you restart the Metro Mirror or Global Mirror relationship there will be an initial period during which Metro Mirror or Global Mirror performs a background copy to resynchronize the volume data on the primary and secondary clusters. During this period the data on the Metro Mirror or Global Mirror auxiliary volumes on the secondary cluster is inconsistent and the volumes could not be used as backup disks by your applications.

Note: To ensure the system has the capacity to handle the background copy load you may want to delay restarting the Metro Mirror or Global Mirror relationship until there is a quiet period when the secondary cluster and the SAN fabric (including the intercluster link) have the required capacity. If the required capacity is not available you might experience another 1920 error and the Metro Mirror or Global Mirror relationship will stop in an inconsistent state.

Note: If the Metro Mirror or Global Mirror relationship has stopped in a consistent state ("consistent-stopped") it is possible to use the data on the Metro Mirror or Global Mirror auxiliary volumes on the secondary cluster as backup disks by your applications. You might therefore want to start a Flash Copy of your Metro Mirror or Global Mirror auxiliary disks on the secondary system before restarting the Metro Mirror or Global Mirror relationship. This means you maintain the current, consistent, image until the time when the Metro Mirror or Global Mirror relationship is again synchronized and in a consistent state.

Possible Cause-FRUs or other:

Other:

Parent topic: Error event IDs and error codes