The presence of redundant delta disks can adversely affect virtual machine performance. You can combine such disks without violating a data dependency. After consolidation, redundant disks are removed, which improves virtual machine performance and saves storage space.

Snapshot consolidation is useful when snapshot disks fail to compress after a Delete or Delete all operation. This might happen, for example, if you delete a snapshot but its associated disk does not commit back to the base disk.

The Needs Consolidation column in the vSphere Client shows the virtual machines to consolidate.

Prerequisites

Required privilege: Virtual machine > Snapshot management > Remove Snapshot

Procedure

  1. Show the Needs Consolidation column for a list of virtual machines.
    1. Navigate to an inventory object that contains a list of virtual machines, for example a vCenter Server instance, a host, or a cluster.
    2. Click the VMs tab and click Virtual Machines.
    3. Click the expand button next to any column names.
    4. Select Show/Hide Columns > Needs Consolidation.

    A Yes status indicates that the snapshot files for the virtual machine should be consolidated, and that the virtual machine's Tasks and Events tab shows a configuration problem. A No status indicates that the files are OK.

  2. To consolidate the files, right-click the virtual machine and select Snapshots > Consolidate.
  3. Check the Needs Consolidation column to verify that the task succeeded.

    If the task succeeds, a Not Required value appears in the Needs Consolidation column.

  4. If the task fails, check the event log for the failure reason.
  5. Correct the error and retry the consolidation task.