6.0

4 Click Yes in the confirmation dialog box.
Subsequent child snapshots from this point create a new branch of the snapshot tree. The delta disks for
snapshots that you took after you restored the current snapshot are not removed and you can restore those
snapshots at any time.
Deleting Snapshots
Deleting a snapshot removes the snapshot from the Snapshot Manager. The snapshot files are consolidated
and written to the parent snapshot disk and merge with the virtual machine base disk.
Deleting a snapshot leaves the current state of the virtual machine or any other snapshot untouched.
Deleting a snapshot consolidates the changes between snapshots and previous disk states and writes to the
parent disk all data from the delta disk that contains the information about the deleted snapshot. When you
delete the base parent snapshot, all changes merge with the base virtual machine disk.
Deleting snapshots involves large amounts of disk reads and writes, which can reduce virtual machine
performance until consolidation is complete. Consolidating snapshots removes redundant disks, which
improves virtual machine performance and saves storage space. The time it takes to delete snapshots and
consolidate the snapshot files depends on the volume of data that the guest operating system wrote to the
virtual disks after you took the last snapshot. The required time is proportional to the amount of data the
virtual machine is writing during consolidation if the virtual machine is powered on.
If disk consolidation fails when you delete a snapshot or delete all snapshots and you notice a degradation
in virtual machine performance, you can view a list of virtual machines to determine if any files require
consolidation, and if so, run a separate consolidation operation. For information about locating and viewing
the consolidation state of multiple virtual machines and running a separate consolidation operation, see
“Consolidate Snapshots in the vSphere Client,” on page 194
Delete
Use the Delete option to remove a single parent or child snapshot from the
snapshot tree. Delete writes disk changes between the snapshot and the
previous delta disk state to the parent 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
Manager. Delete all consolidates and writes changes between snapshots and
previous delta disk states to the base parent disk and merges them with the
base virtual machine disk.
To prevent snapshot files from merging with the parent snapshot, for example in cases of failed updates or
installations, first use the Go to command to restore 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.
Delete a Snapshot in the vSphere Client
You can use the Snapshot Manager to delete a single snapshot or all snapshots in a snapshot tree.
Use care when you delete snapshots. You cannot restore 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 restore 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.
Chapter 16 Managing Virtual Machines
VMware, Inc. 193