Deleting a snapshot permanently removes the snapshot from the snapshot tree. The snapshot files are consolidated and written to the parent snapshot disk and merge with the virtual machine base disk. You can delete a single snapshot or all snapshots in a snapshot tree.

Deleting a snapshot does not change the virtual machine or other snapshots. Deleting a snapshot consolidates the changes between snapshots and previous disk states. Then it writes all the data from the delta disk that contains the information about the deleted snapshot to the parent disk. When you delete the base parent snapshot, all changes merge with the base virtual machine disk.

To delete a snapshot, a large amount of information must be read and written to a disk. This process can reduce the virtual machine performance until the consolidation is complete. Consolidating snapshots removes redundant disks, which improves the virtual machine performance and saves storage space. The time to delete snapshots and consolidate the snapshot files depends on the amount of data that the guest operating system writes to the virtual disks after you take the last snapshot. If the virtual machine is powered on, the required time is proportional to the amount of data the virtual machine is writing during consolidation.

Failure of disk consolidation can reduce the performance of virtual machines. You can check whether any virtual machines require separate consolidation operations by viewing a list. For information about locating and viewing the consolidation state of multiple virtual machines and running a separate consolidation operation, see vSphere Virtual Machine Administration.

Delete
Use the Delete option to remove a single parent or child snapshot from the snapshot tree. This option writes disk changes that occur between the state of the snapshot and the previous disk state to the parent snapshot.
Note: Deleting a single snapshot preserves the current state of the virtual machine and does not affect any other snapshot.

You can also use the Delete option to remove a corrupt snapshot and its files from an abandoned branch of the snapshot tree without merging them with the parent snapshot.

Delete All
Use the Delete All option to delete all snapshots from the snapshot tree. The Delete all option consolidates and writes the changes that occur between snapshots and the previous delta disk states to the base parent disk. It then merges them with the base virtual machine disk.

To prevent snapshot files from merging with the parent snapshot if, for example, an update or installation fails, first use the Revert button to revert to a previous snapshot. This action invalidates the snapshot delta disks and deletes the memory file. You can then use the Delete option to remove the snapshot and any associated files.

Caution: Use care when you delete snapshots. You cannot revert a deleted snapshot. For example, you might want to install several browsers, a, b, and c, and capture the virtual machine state after you install each browser. The first, or base snapshot, captures the virtual machine with browser a and the second snapshot captures browser b. If you revert the base snapshot that includes browser a and take a third snapshot to capture browser c, and delete the snapshot that contains browser b, you cannot return to the virtual machine state that includes browser b.

Prerequisites

  • Familiarize yourself with the delete and delete all actions and how they affect virtual machine performance.
  • Required Privilege: Virtual machine.Snapshot management.Remove Snapshot on the virtual machine.

Procedure

  • To delete snapshots from a snapshot tree, navigate to a virtual machine in the vSphere Web Client inventory and click the Snapshots tab.
    Option Action
    Delete a single snapshot
    1. Navigate to and select a snapshot in the snapshots tree.
    2. Click Delete and click the Delete button.

      The snapshot data is consolidated to the parent snapshot and the selected snapshot is removed from the snapshot tree.

    Delete all snapshots
    1. Click Delete All and click the Delete all button.

      All immediate snapshots before the You are here current state are consolidated to the base parent disk. All existing snapshots are removed from the snapshot tree and the virtual machine.