• Configuring LUN move

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    Configuring LUN move

    About LUN Move sessions

    The LUN Move feature lets you move block storage resources:

    • To a pool with faster drives.
    • Between pools for load balancing.
    • To take advantage of newly purchased spindles.
    • To convert a thin LUN to a thick LUN, or a thick LUN to a thin LUN.
    • To enable data reduction (for either newly-written data or both newly-written data and existing data) on a thin LUN in an All-Flash pool. If you choose to apply data reduction to existing data, choose the pool where you want to move the LUN data.

    You can move LUNs, member LUNs in a consistency group, and VMware VMFS LUNs. However, you cannot move thin clones or storage resources that have derived thin clones.

    If LUNs have associated snapshots, the snapshots are deleted once the move completes successfully.

    While a storage resource is being moved, you can view the status from the storage resource's summary and properties pages. Once completed, the move status can be viewed for up to three days from the same two pages.

    LUN move session restrictions and limitations

    A LUN move session cannot start if:

    • A storage system NDU is in progress.
    • The destination pool does not have enough space.
    • A LUN expand or shrink operation is in progress.
    • The source LUN is being restored from a snapshot.
    • An import from a VNX LUN to the source LUN is in progress.
    • The source LUN is flagged as requiring recovery.
    • The source LUN is offline.
    • Replication is enabled, and the LUN is a replication source or destination. Turn off replication prior to starting a move session.

    During a LUN move session, you cannot:

    • Delete the source LUN.
    • Create a snapshot of the source LUN.
    • Restore the source LUN from a snapshot.
    • Add or remove the source LUN from a consistency group.
    • Start an import from a VNX LUN to the source LUN.
    • Perform an expand or shrink operation on the source LUN.
    • Start an NDU of the storage system.
    • Start a recovery operation on the source LUN.
    • Configure a LUN for replication.

    Create a LUN move session

    Before you begin

    Be aware that a LUN move session cannot start if:

    • A storage system NDU is in progress.
    • The destination pool does not have enough space.
    • A LUN expand or shrink operation is in progress.
    • The source LUN is being restored from a snapshot.
    • An import from a VNX LUN to the source LUN is in progress.
    • The source LUN is flagged as requiring recovery.
    • The source LUN is offline.
    • Replication is enabled, and the LUN is a replication source or destination. Turn off replication prior to starting a move session.

    See LUN move session restrictions and limitations for additional details.

    Procedure
    1. Under Storage, select Block > LUNs.
    2. Select More Actions > Move.
    3. On the Move LUN window, specify the relevant information.
    4. Click OK.
      If the source LUN contains snapshots, a warning is issued, and the move continues. Once the move completes successfully, the system deletes the snapshots. You can then create snapshots on the new LUN.

    Cancel a LUN move session

    Before you begin

    A LUN move session must be in progress to be cancelled.

    Procedure
    1. Under Storage, select Block > LUNs.
    2. Select More Actions > Cancel Move.
    3. Click Yes.

    Best practices for LUN move sessions

    The following describes best practices to be aware of when moving LUNs in a system:

    1. You should properly plan the migration before the move. For example, determine the new storage requirements, locate the destination storage pool, and determine if the pool is suitable (for example, that there is enough space available).
    2. Be aware that no manual cut over is required. Once the move operation starts, the system will cutover to the new storage automatically at the completion of a successful move.
    3. Be aware of the move session priority option. The priority of a session indicates the amount of resources devoted to that session compared to other move sessions. It does not pertain to the throttle of a session.

    Troubleshooting LUN move session issues

    The following table describes common issues that can occur during a LUN move operation, and how to resolve them.

    Table 1. LUN move troubleshooting information
    Issue
    Resolution
    Destination pool does not have sufficient space to start the move operation, or the pool exhausted the space available during a move operation.

    To resolve this issue:

    1. Delete the move session.
    2. Add more space to the destination pool.
    3. Recreate the move session.

    This issue may occur:

    • When you first attempt to create a move session.
    • While the move operation is running.

    It is possible that the destination pool had enough space when the move operation first started, but more space was consumed on the destination while the move was in progress.

    Destination pool is in the process of being destroyed.
    Choose a different destination pool.
    A prior NDU has not been committed.
    Commit the NDU.
    The move session maximum limit of 100 has been reached.
    Wait until a move session completes, or cancel a lower priority move session, before adding another move session.
    Snapshots disappeared after the move operation completed.
    Expected behavior. You are allowed to create a LUN move session if the LUN has snapshots, but the snapshots are deleted after the move operation completes. You need to recreate the snapshots.
    Cannot create a new snapshot after the move operation begins.
    Expected behavior. Recreate snapshots after the move operation completes.
    Cannot start a LUN expansion or shrink during a move operation.
    Expected behavior. Start a LUN expansion or shrink operation after the move operation completes.
    Cannot start a move operation while a LUN expansion or shrink is in progress.
    Expected behavior. Wait for the LUN expansion or shrink operation to complete before starting a move session.