VMware ESXi and vSphere Cluster Management

How to Take Virtual Machine Snapshots in VMware ESXi

Learn how to create and verify VMware ESXi virtual machine snapshots in the vSphere Web Client, choose memory and quiescing options, and manage snapshot storage safely.

A virtual machine snapshot is a point-in-time record of selected virtual machine state. You can use it to return a VM to an earlier condition after a configuration change, software installation, patch, or test.

Snapshots are designed for short-term rollback. They are not a substitute for backups because they depend on the VM and its datastore, can grow as the VM writes data, and do not by themselves provide an independent copy for disaster recovery.

How a VMware snapshot works

When you create a snapshot, vSphere records the VM's virtual disk state and configuration state at that moment. The snapshot is not a standalone full copy of the VM. After creation, later disk writes are recorded in additional snapshot-related files on the VM's datastore, the storage location for VM files.

A snapshot can include the following:

Virtual disk state: The disk contents represented at the time the snapshot is created.
VM configuration state: VM settings such as virtual hardware and configuration information.
Memory state: The contents of the VM's RAM, but only when the memory option is selected for a running VM.

The revert action returns the VM to the state represented by a selected snapshot. Changes made after that snapshot can be discarded, so preserve important changes through another snapshot, a backup, or another approved protection method before reverting.

VM states supported for snapshot creation

You can create a snapshot while a VM is powered on, powered off, or suspended. The power state affects which capture options are useful and how recovery behaves.

VM Power State	Can Create Snapshot	Relevant Considerations
Powered on	Yes	You can capture disk and configuration state. You may also select memory capture to preserve the running execution state. Alternatively, with memory capture disabled, you may select guest file system quiescing when VMware Tools supports it.
Powered off	Yes	There is no running RAM state to preserve. The snapshot records disk and configuration state without capturing an active guest session.
Suspended	Yes	The VM already has a suspended execution state. Review the available options and the resulting recovery behavior before creating the snapshot.

For a running development VM where returning to the same in-progress session matters, memory capture may be appropriate. For a short maintenance task where disk consistency matters more than preserving the running session, disable memory capture and consider guest file system quiescing.

Snapshot creation options

Option	What It Captures or Does	Requirements	When to Use	Important Limitation
Snapshot the virtual machine's memory	Saves the contents of the VM's RAM along with its disk and configuration state.	Most relevant when the VM is powered on.	Use when resuming the same in-progress execution state after a revert is important, such as for a powered-on test VM.	Increases the amount of data and processing involved. It must be disabled before guest file system quiescing can be selected.
Quiesce guest file system	Attempts to place the guest file system into a consistent state before the disk snapshot is taken.	VMware Tools must be installed and running in the guest OS. Memory capture must be disabled.	Use for a short maintenance or change window when file-system-consistent disk state is desired.	It does not necessarily quiesce running applications or guarantee application-consistent recovery.
Neither option selected	Captures disk and configuration state without saving RAM or requesting guest file system quiescing.	No memory capture or quiescing prerequisite.	Use for a basic rollback point when the other options are unnecessary.	The result may not represent a quiesced guest file system or a saved running session.

Snapshot memory

Snapshot memory captures the contents of the VM's RAM. If the VM is powered on and memory capture succeeds, reverting can allow the VM to resume from the captured execution state rather than starting only from disk and configuration state.

Memory capture requires additional data and processing. It can make the operation take longer and can increase the storage and capacity impact associated with the snapshot. Do not select it automatically; choose it when preserving the active session is part of the rollback requirement.

Guest file system quiescing

Guest file system quiescing is a process intended to create a file-system-consistent disk state before the snapshot is taken. vSphere requests this cooperation through VMware Tools, guest software that enables management operations between vSphere and the guest operating system.

Quiescing helps protect the consistency of data already being written to disk, but it does not necessarily pause or coordinate every application. A database or other transactional application may require its own application-aware backup or consistency process.

The two options have a dependency: clear Snapshot the virtual machine's memory before selecting Quiesce guest file system. If the quiescing option is unavailable, verify both that memory capture is disabled and that VMware Tools is installed, running, and healthy in the guest.

Create a snapshot in the vSphere Web Client

The vSphere Web Client is the vSphere management interface used to select VMs and start snapshot operations. Menu names can vary slightly between vSphere releases, but the workflow is the same.

Locate the VM: In the vSphere inventory, select the target virtual machine. Confirm its name and, when relevant, its host, cluster, and datastore so that you do not snapshot the wrong VM.
Open the snapshot action: Right-click the VM and choose Take Snapshot, or select the equivalent VM actions menu and choose the snapshot command.
Enter a meaningful name: Include the purpose and a date or change window. For example, use before-network-change-2026-08-17 rather than a name such as snapshot1.
Add a description: Record the change, test, expected rollback condition, and owner or maintenance window. For example: Rollback point before changing the application VM network settings; remove after validation.
Choose memory capture: Select the memory option only when preserving the running VM session is important. Leave it clear for a basic disk and configuration snapshot or when you want to enable quiescing.
Choose guest file system quiescing when appropriate: With memory capture disabled, select quiescing if VMware Tools is installed and running and a file-system-consistent disk state is needed.
Confirm the request: Submit the snapshot creation request. Monitor the task until it completes successfully; do not assume the snapshot exists merely because the dialog closed.
Verify the result: Select the VM, choose Manage Snapshots, and inspect the snapshot tree for the new name and description.

Verify and manage snapshots with Snapshot Manager

Snapshot Manager is the vSphere interface for viewing and managing a VM's snapshot tree. A snapshot tree is the parent-child hierarchy that represents multiple snapshots and branches for one VM.

Select the intended VM in the inventory.
Choose Manage Snapshots from the VM actions or management menu.
Confirm that the new snapshot appears in the tree.
Check the snapshot name and description, then review its parent-child position if other snapshots already exist.
Use the available Snapshot Manager actions only after confirming that the selected snapshot and VM are correct.

Snapshot Manager is the place to review snapshot names, descriptions, relationships, and actions such as creating another snapshot, reverting, or deleting a snapshot. Check recent tasks and events if the expected snapshot is not visible.

Snapshot management actions

Action	Purpose	Effect on Later Changes
Create snapshot	Creates a new point-in-time record of selected VM state.	Later virtual disk writes are tracked separately while the snapshot exists.
View in Snapshot Manager	Displays the snapshot tree, names, descriptions, relationships, and available actions.	Does not change the VM or its later changes.
Revert to snapshot	Returns the VM to the state represented by the selected snapshot.	Changes made after the selected snapshot may be discarded unless preserved elsewhere.
Delete or remove snapshot	Removes the selected snapshot and causes vSphere to merge or consolidate relevant disk changes as required.	It removes that rollback point; it does not mean that later changes are retained as a separate restore point.

Storage and snapshot file considerations

A snapshot does not produce a standalone full VM copy. It creates additional VM-related files on the datastore and changes how subsequent virtual disk writes are recorded. The longer the snapshot remains and the more data the VM writes, the more snapshot storage can grow.

Monitor free datastore capacity while snapshots exist.
Pay particular attention to write-intensive VMs such as databases, logging systems, and build servers.
Account for memory capture because it increases the data involved in the operation.
Do not leave snapshots indefinitely as a backup strategy.
Remove or consolidate snapshots after the rollback window closes, following your operational procedures.

Snapshot removal or consolidation can itself require time and datastore I/O. Plan the operation and ensure adequate free space rather than waiting until the datastore is nearly full. Related storage topics include browsing VMFS datastores and consolidating snapshots.

Practical examples

Pre-change rollback point

Before changing a VM's network settings or installing an application update, create a snapshot named before-app-update-2026-08-17. Describe the intended change and rollback condition. Validate the VM, then remove the snapshot when the change window closes.

Powered-on test VM

A developer is testing a long-running process in a powered-on VM and needs to return to the same in-progress session. Create a snapshot with memory capture selected, understanding that the operation requires more storage and processing than a disk-and-configuration snapshot.

File-consistent disk snapshot

Before a short maintenance task, create a snapshot with memory capture disabled and guest file system quiescing enabled. First verify that VMware Tools is installed and running. This improves file-system consistency, but application-specific protection may still be required.

Snapshot verification

After the task completes, open Manage Snapshots for the intended VM. Confirm that the expected name and description appear in the snapshot tree, especially if the environment contains similarly named VMs or multiple snapshot branches.

Troubleshooting snapshot creation and verification

The Quiesce guest file system option is unavailable

Clear Snapshot the virtual machine's memory; quiescing cannot be selected while memory capture is enabled.
Verify that VMware Tools is installed in the guest operating system.
Verify that VMware Tools is running and healthy, then retry the operation.

The operation takes longer than expected or datastore capacity declines

Check whether the VM is generating substantial disk writes after snapshot creation.
Review the snapshot's age and growth in Snapshot Manager and the datastore view.
Remember that memory capture increases the data involved.
Confirm sufficient free datastore space and remove or consolidate snapshots after they are no longer needed.

The snapshot does not provide application-consistent recovery

Guest file system quiescing is different from application quiescing. If quiescing was not enabled, or if the application needs coordinated transaction handling, use an application-aware backup or protection process. A file-system-consistent snapshot alone may not be sufficient for databases and similar workloads.

The expected snapshot cannot be found

Confirm that you are viewing the intended VM rather than another VM with a similar name.
Check recent tasks and events to determine whether creation completed successfully.
Open Snapshot Manager and inspect all branches of the snapshot tree.
Use descriptive names and descriptions to distinguish restore points.

Operational guidance and exam notes

Use snapshots before risky configuration changes, software installation, patching, or testing when short-term rollback is useful.
Name snapshots by purpose and date or change window, and document the expected removal time.
Keep snapshots only for as long as the rollback window requires, particularly on write-intensive VMs.
Monitor datastore capacity throughout the snapshot lifecycle.
Remember that snapshots are not backups.
Reverting discards post-snapshot changes unless those changes were preserved through another snapshot or backup.
For a powered-on VM, memory capture preserves RAM state but increases processing and storage requirements.
Guest file system quiescing requires VMware Tools and requires memory capture to be disabled.
Quiescing improves file-system consistency but does not guarantee application consistency.

For broader vSphere administration practice, see the VMware ESXi online course and related guidance on vSphere tasks and events monitoring where available in your environment.