A VMware snapshot is a copy of a virtual machines disk file (VMDK) at a given point in time. It captures the state and data of a virtual machine at a specific time when the snapshot was taken. Snapshots provide a change log for the virtual disk and are used to restore a VM to a particular point. Any data that was writable on a VM becomes read-only when the snapshot is taken. VMware administrators can take multiple snapshots of a VM to create multiple possible point-in-time restore points. When a VM reverts to a snapshot, current disk and memory states are deleted, and the snapshot becomes the new parent snapshot for that VM. The snapshot file cannot exceed the size of the original disk file, and it requires some overhead disk space. Snapshots will grow rapidly with high disk-write activity volume, and most snapshots are deleted within an hour. VMware recommends deleting snapshots within 24 hours.
It is important to note that snapshots should not be considered as a backup for any virtual machine. While a snapshot can be used to revert to a previous state of a virtual machine, it is not a substitute for a proper backup solution. Snapshots can also affect the performance of a virtual machine because they utilize the same resources as the original virtual machine.
To take a snapshot in VMware, you can navigate to the VMware menu and select "Snapshot". The snapshot manager allows you to preserve the state and data of a virtual machine at a specific point in time. Once you take a snapshot, you can restore back to that point. Snapshots are often used for quick "rinse and repeat" type operations, especially in a development environment, such as before testing a software process on a virtual machine.
