4.6 Using Dynamic File Services in a Windows Cluster

Dynamic File Services supports using pairs and policies in a Windows failover cluster. However, DynamicFS is not cluster aware.

This section describes known issues for using DynamicFS in a Windows cluster.

4.6.1 Dynamic File Services Management Console

When you use the Management Console to manage the Dynamic File Service in a cluster, use the cluster resource IP address of the Service to connect to the cluster instead of the server node’s IP address.

When you create pairs and policies, ensure that the primary path and secondary path meet the requirements specified in Section 4.1.2, Shared Disks.

4.6.2 Dynamic File Service Controller

The Dynamic File Service Controller starts automatically at the beginning of each session when you log in to the active node where the disk that contains the Dynamic File Services folder is currently mounted. The controller does not start if you log in to the failover node because the shared disk is not mounted there.

4.6.3 Dynamic File Service and Executable Files

The Dynamic File Service is started automatically by the Windows cluster management tool when it brings the Dynamic File Service cluster resource online. The Dynamic File Service is stopped when the Windows cluster management tool brings the resource offline. Ensure that you use the Windows cluster management tool to start and stop the Service, not the Dynamic File Service controller.

Other DynamicFS executable files are called from the Dynamic File Service, or can be started manually when you are logged in as a user with Administrator privileges on the active node. Conversely, you cannot start the executable files on the failover node because the cluster drive resource that contains the files is not attached to it.

4.6.4 Moving the Dynamic File Service Cluster Resource Between Nodes

Before initiating a non-failover move of the Dynamic File Service cluster resource from the active node to a failover node, you must quiesce the Service as described in Prerequisites for Stopping or Restarting the Service in the Dynamic File Services Administration Guide .

You should not issue a cluster move while a policy run is in progress. If a policy is running when the move is initiated, the resource enters an Offline Pending state until DynamicFS can gracefully complete the in-progress file copies, shut down the policy run, and go offline for the move. This process can take up to 10 minutes. During this time, the failover cluster File Server and IP address for the Dynamic File Service are unavailable, and users cannot access the files.

If the active node crashes when a policy run is in progress, the Dynamic File Service also crashes. The Dynamic File Service cluster resource immediately goes offline and fails over to the failover node. The following issues must be addressed after the Dynamic File Service cluster resource is back online:

  • The policy run does not automatically resume or start over after the failover.

  • There is no ability to gracefully complete any file copies that are in progress for the policy run.

    There is no data loss, but duplicate files might exist, where the original file is good but the copy of the file that was being moved by a policy is only a sparse file in the target location.

    To resolve this problem:

    1. Run the Pair Check utility on each pair to check for duplicate files in the pairs where the policy was running. For information, see Reporting Conflicts for Duplicate Files in the Dynamic File Services 2.2 Administration Guide.

    2. For each reported duplicate file conflict, delete the copy of the file in the target location of the policy move.

    3. After all duplicate file conflicts have been resolved, you can start the policy run manually, or let the policy run at its next scheduled time.