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Volume reuse after data migration

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After performing a nondisruptive data migration using global-active device (GAD) and discontinuing GAD operations, you can reuse the volumes at both sites.

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Reusing volumes after data migration

This topic provides instructions for reusing volumes that were the P-VOLs and S-VOLs of GAD pairs that have been deleted.

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Child Topics

Reusing a volume that was an S-VOL

When you delete a GAD pair by specifying the P-VOL, the GAD reserve attribute remains set for the volume that was the S-VOL. When you delete a GAD pair by specifying the S-VOL, the GAD reserve attribute is applied to the volume that was the P-VOL. When you check a volume that has the reserve attribute using the raidcom get ldev command, the virtual LDEV ID (VIR_LDEV) is displayed as ffff.

Procedure

  1. Delete the LU path to the volume that has the reserve attribute.

  2. Remove the reserve attribute.

    Command example for removing the reserve attribute set for LDEV ID (0x4444): 

    raidcom unmap resource -ldev_id 0x4444 -virtual_ldev_id reserve

    The volume from which the reserve attribute was removed changes to a volume whose virtual LDEV ID was deleted. If you use the raidcom get ldev command to check a volume whose virtual LDEV ID was deleted, the virtual LDEV ID (VIR_LDEV) is displayed as fffe.

  3. Reserve an LDEV ID for the resource group that will use the volume.

    Command example for reserving LDEV ID (0x4444) for resource group (#0): 

    raidcom add resource -resource_name meta_resource -ldev_id 0x4444

  4. Set a virtual LDEV ID for the volume.

    NoteYou must set a virtual LDEV ID that is unique within the storage system that uses the volume. If the same virtual LDEV ID is used in other storage systems or virtual storage machines with the same serial number and model, identification of multiple volumes with the same virtual LDEV ID might cause problems. At worst, the server might detect an inconsistency.

    Command example for setting virtual LDEV ID (0x5555) for volume (0x4444): 

    raidcom map resource -ldev_id 0x4444 -virtual_ldev_id 0x5555

  5. Specify a new port and host group for the volume, and set an LU path.

Parent Topic

Reusing a volume that was a P-VOL

After you delete a GAD pair by specifying the P-VOL, you can continue to use the volume that was the P-VOL of the pair. When you execute the raidcom get ldev command for a volume that continues to be available after pair deletion, a value other than ffff or fffe is displayed for the VIR_LDEV (virtual LDEV ID), or the VIR_LDEV is not displayed.

Use the following procedure to move the volume to another resource group (virtual storage machine) so that the server recognizes it as a different volume and it can be used.

Procedure

  1. Delete the LU path to the volume.

  2. Delete the virtual LDEV ID.

    Command example for deleting virtual LDEV ID (0x5555) set for LDEV ID (0x4444): 

    raidcom unmap resource -ldev_id 0x4444 -virtual_ldev_id 0x5555

    When you delete the virtual LDEV ID, the volume changes to a volume whose virtual LDEV ID has been deleted. If you execute the raidcom get ldev command for a volume whose virtual LDEV ID has been deleted, fffe is displayed for the VIR_LDEV (virtual LDEV ID).

  3. Reserve an LDEV ID for a resource group to be used for a different purpose.

    Command example for reserving LDEV ID (0x4444) for resource group (AnotherGroup) to which the volume is registered:

    raidcom add resource -resource_name AnotherGroup -ldev_id 0x4444

  4. Set a virtual LDEV ID for the volume.

    NoteYou must set a virtual LDEV ID that is unique within the storage system that uses the volume. If the same virtual LDEV ID is used in other storage systems or virtual storage machines with the same serial number and model, identification of multiple volumes with the same virtual LDEV ID might cause problems. At worst, the server might detect an inconsistency.

    Command example for setting virtual LDEV ID (0xe000) for volume (0x4444):

    raidcom map resource -ldev_id 0x4444 -virtual_ldev_id 0xe000

  5. Specify a new port and host group for the volume, and set an LU path.

Parent Topic

Deleting used volumes

Deleting volumes only does not change the virtual LDEV ID. Therefore, if you do not plan to re-create the GAD pair with the volumes you delete, you must also delete the virtual LDEV ID.

If you re-create the volume you delete, the same virtaul LDEV ID as the deleted volume is assigned.

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Child Topics

Deleting a volume with the reserve attribute

When you delete a GAD pair by specifying the P-VOL, the GAD reserve attribute remains set for the volume that was the S-VOL. When you delete a GAD pair by specifying the S-VOL, the GAD reserve attribute is applied to the volume that was the P-VOL.

When you check a volume that has the reserve attribute using the raidcom get ldev command, the virtual LDEV ID (VIR_LDEV) is displayed as ffff.

Procedure

  1. Delete the LU path to the volume that has the reserve attribute.

  2. Remove the reserve attribute.

    Command example for removing the reserve attribute set for LDEV ID (0x4444): 
    raidcom unmap resource -ldev_id 0x4444 -virtual_ldev_id reserve

    The volume from which the reserve attribute was removed changes to a volume whose virtual LDEV ID was deleted. If you use the raidcom get ldev command to check a volume whose virtual LDEV ID was deleted, the virutal LDEV ID (VIR_LDEV) is displayed as fffe.

  3. Delete the virtual LDEV ID from the resource group.

    Command example for deleting virtual LDEV ID (0x4444) from resource group (AnotherGroup), and then moving the virtual LDEV ID to meta_resource: 
    raidcom delete resource -resource_name AnotherGroup -ldev_id 0x4444

  4. Set a virtual LDEV ID for the volume.

    Command example for setting virtual LDEV ID (0x4444) for volume (0x4444): 
    raidcom map resource -ldev_id 0x4444 -virtual_ldev_id 0x4444

  5. Delete the volume.

    Command example: 
    raidcom delete ldev -ldev_id 0x4444
Parent Topic

Deleting a volume that was a P-VOL

When you delete a volume that was a P-VOL, you must also delete the virtual LDEV ID for the volume.

Procedure

  1. Delete the LU path to the volume.

  2. Delete the virtual LDEV ID.

    Command example for deleting virtual LDEV ID (0x5555) set for LDEV ID (0x4444): 

    raidcom unmap resource -ldev_id 0x4444 -virtual_ldev_id 0x5555

    When you delete the virtual LDEV ID, the volume changes to a volume whose virtual LDEV ID has been deleted. If you use the raidcom get ldev command for a volume whose virtual LDEV ID has been deleted, fffe is displayed for the VIR_LDEV (virtual LDEV ID).

  3. When the virtual LDEV ID is reserved by the resource group other than meta_resource, delete the virtual LDEV ID from the resource group.

    Command example for deleting virtual LDEV ID (0x4444) from resource group (AnotherGroup), and then moving the virtual LDEV ID to meta_resource: 
    raidcom delete resource -resource_name AnotherGroup -ldev_id 0x4444

  4. Set a virtual LDEV ID for the volume.

    Command example for setting virtual LDEV ID (0x4444) for volume (0x4444): 
    raidcom map resource -ldev_id 0x4444 -virtual_ldev_id 0x4444

  5. Delete the volume.

    Command example: 
    raidcom delete ldev -ldev_id 0x4444
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