VMware Workstation 4.5
The snapshot feature is most useful when you want to preserve the state of the virtual machine so you can return to the same state repeatedly.
To simply save the current state of your virtual machine, then pick up work later with the virtual machine in the same state it was when you stopped, suspend the virtual machine. For details, see Using Suspend and Resume.
You can take a snapshot while a virtual machine is powered on, powered off or suspended. (If you are suspending a virtual machine, wait until the suspend operation has finished before taking the snapshot.) A snapshot preserves the virtual machine just as it was when you took the snapshot the state of the data on all the virtual machine's disks and whether the virtual machine was powered on, powered off or suspended. You can then revert to that snapshot at any time.
Note: If you are using a legacy virtual machine a virtual machine created under VMware Workstation 3 and not upgraded to use the new VMware Workstation 4 virtual hardware you must power off the virtual machine before taking a snapshot. For information on upgrading the virtual hardware, see Upgrading VMware Workstation. You also must power off the virtual machine before taking a snapshot if the virtual machine has multiple disks in different disk modes for example, if you have a special purpose configuration that requires you to use an independent disk.
When you revert to a snapshot, you discard all changes made to the virtual machine since you took the snapshot.
Use the Snapshot and Revert buttons on the Workstation toolbar to take a snapshot and revert to it later.
You can take a new snapshot at almost any time. When you take a new snapshot, you replace the previous snapshot. You can have only one active snapshot at a time.
The snapshot captures the entire state of the virtual machine at the time you take the snapshot. This includes:
When you revert to the snapshot, you return all these items to the state they were in at the time you took the snapshot.
Note: In certain special purpose configurations, you may want to exclude one or more of the virtual machine's disks from the snapshot. To exclude a disk from the snapshot, choose VM > Settings, select the drive you want to exclude, then click Advanced. On the advanced settings screen, select Independent. You have the following options for an independent disk:
You can also specify what you want VMware Workstation to do with the snapshot any time the virtual machine is powered off. To do so, go to VM > Settings > Options > Snapshot and select one of the choices under When powering off.
Options when powering off include
If the virtual machine has no snapshot, you can disable the snapshot feature by selecting Disable snapshots. If you have a snapshot and want to disable the snapshot feature, first go to the VMware Workstation menu and choose Snapshot > Remove Snapshot. Then return to the virtual machine settings editor and select Disable snapshots.
To lock the snapshot so no new snapshot can be taken, select Lock this snapshot.
When you change settings in the virtual machine settings editor, you may want to update the snapshot so these new settings are in effect when you revert to the snapshot. The most convenient way to do so is to select Update the snapshot after changing settings at the bottom of the virtual machine settings editor.
If this option is selected, when you click OK in the virtual machine settings editor, VMware Workstation updates the snapshot of the virtual machine. To avoid updating the snapshot, click Cancel or deselect Update the snapshot after changing settings before you click OK.
You can remove the snapshot any time the virtual machine is powered off. Removing the snapshot does not destroy any data in the virtual machine. You keep all changes made since you took the snapshot. For example, changes made to data stored on the virtual hard disk are written to the virtual disk files. You then permanently accumulate additional changes as you run the virtual machine. You cannot revert to a previous state because the snapshot no longer exists.
To remove the snapshot, shut down and power off the virtual machine. Then, on the VMware Workstation menu, choose Snapshot > Remove Snapshot.
The following examples illustrate the most common ways you can use the snapshot.
If you do not take a snapshot, your virtual machine runs the same way a physical computer does. All changes you make while you are working with a virtual machine are saved and you cannot return to an earlier state.
If you do not need to use the snapshot feature, it is best to run your virtual machine with no snapshot. This provides best performance. To be sure a virtual machine has no snapshot, choose Snapshot > Remove Snapshot. You can then disable the snapshot functionality for the virtual machine. Go to VM > Settings > Options > Snapshot and select Disable snapshots.
If you plan to make risky changes in a virtual machine (for example, testing new software or examining a virus), take a snapshot before you begin to make those risky changes. If you encounter a problem, click Revert to return the virtual machine to its state at the time you took the snapshot.
If the first action you take causes no problems and you want to protect the virtual machine in its new state, you can take a new snapshot. You can have only one snapshot at a given time. When you take the new snapshot, you replace your previous snapshot. You do not lose any data. For example, changes made to data stored on the virtual hard disk are written to the virtual disk files.
You can configure the virtual machine to revert to the snapshot any time it is powered off. To do so, go to VM > Settings > Options > Snapshot. Under When powering off, select Revert to the snapshot. If you want the virtual machine to be suspended when you launch it, suspend the virtual machine before saving the snapshot. Similarly, if you want the virtual machine to be powered on or powered off when you launch it, be sure it is powered on or powered off when you take the snapshot.
If you are familiar with the disk modes used in earlier versions of VMware Workstation, you can use the snapshot to achieve equivalent results.
Note: In earlier versions of VMware Workstation, disk modes had to be set individually for each disk. The snapshot introduced in VMware Workstation 4 applies by default to the entire virtual machine, including all disks attached to the virtual machine.
The repeatable resume feature in earlier versions of Workstation allowed you to resume a suspended virtual machine repeatedly in the same state. You can use the snapshot to accomplish the same thing. Run the virtual machine, be sure it is in the state you want it, then suspend it. Take a snapshot. Go to VM > Settings > Options > Snapshot. Under When powering off, select Revert to the snapshot.
If you are using a legacy virtual machine a virtual machine created under VMware Workstation 3 and not upgraded to use the new VMware Workstation 4 virtual hardware and you have disks in undoable or nonpersistent mode, you have a snapshot. If you have persistent disks, you have no snapshot. You have the following options:
When a snapshot exists and the virtual machine saves data to disk, that data is written to a set of redo-log files. These files have .REDO as part of the filename and are stored in the virtual machine's working directory.
Newly saved data continues to accumulate in the redo-log files until you take an action that affects the snapshot.
When you take a snapshot, be aware of other activity going on in the virtual machine and the likely impact of reverting to the snapshot. In general, it is best to take the snapshot when no applications in the virtual machine are communicating with other computers.
The potential for problems is greatest if the virtual machine is communicating with another computer, especially in a production environment.
Consider a case in which you take a snapshot while the virtual machine is downloading a file from a server on the network. After you take the snapshot, the virtual machine continues downloading the file, communicating its progress to the server. If you revert to the snapshot, communications between the virtual machine and the server are confused and the file transfer fails.
Or consider a case in which you take a snapshot while an application in the virtual machine is sending a transaction to a database on a separate machine. If you revert to the snapshot especially if you revert after the transaction starts but before it has been committed the database is likely to be confused.