Detach Shared Volumes operation

Use the Detach Shared Volumes operation to detach selected volumes from all IBM Storage Scale Servers in the cluster, and re-configure the IBM Storage Scale file system.

Before you begin

Review the following information before you attempt to detach a shared volume:
  • You must have at least one more volume attached to the same file system before you attempt to detach a volume, otherwise the operation fails. If no volumes are attached to the file system, the file system cannot exist.
  • When a volume is detached, the IBM Storage Scale disk is removed and data is moved to the other volumes mounted by the file system. The file system is rebalanced. Before you detach a volume, ensure that the other volumes have enough space to store the data from the detached volume. For more information, see the related links.
Restriction: Volumes cannot be attached or detached from virtual machines that have snapshots. Before you detach a volume, check and delete any existing snapshot.

About this task

Do not run the Detach Shared Volumes operation at the same time on multiple instances in the cluster. For example, run the operation to detach volumes from the Primary configuration instance, wait for completion, then run the operation on the Mirror configuration instance, wait for completion, and finally run the operation on the Tiebreaker configuration instance.

Procedure

  1. Expand the Manage Storage Volumes section of the GPFS_Manager operations.
  2. Expand the Detach Shared Volumes node.
  3. To optionally remove the disk definition, select the Remove GPFS disk definition check box.

    This check box is selected by default, and should be selected in most cases. This option migrates all data from the removed disks to other disks in this file system. It then removes the disks from the file system descriptor and re-stripes the remaining disks to rebalance the data. You should typically ensure that this check box is selected, unless you know that IBM Storage Scale definitions have already been removed, or if you only need to detach the LUN.

    You should clear this check box option in situations where you want to detach the volume without deleting the disk definition:
    • Disks are being detached and replaced with an exact replica.
    Otherwise if this option is not selected, any data stored on deleted disks is lost, the file system descriptor has an incorrect disk definition, and the mount might become lost.
    Note: Between the time that you detach the old disk and the time that you attach its successor, clients will lose access to the file system. Ensure that this does not cause problems in your environment before you perform this operation.
  4. In the Shared Volumes field, click Select to select one or more shared volumes to be detached from this IBM Storage Scale configuration.
  5. Click Submit.
  6. Click Confirm when asked to validate your request.

Results

A new entry is displayed under the Operation Execution Results list, with the name Detach Shared Volume. When completed, the status of the operation changes from Active to Done, and the Return Value column displays a message that the operation has been performed, and a link to the resulting log file, similar to the following example:
GPFS-Manager.11402320054789.GPFS_Manager: Detach volume has been invoked. Click here to open the log status.

Click the link to display the log results showing the list of shared volumes that have been detached from each IBM Storage Scale Server virtual machine. Verify that there are no errors in this log.