Snapshots and Other Activity in the Virtual Machine

When you take a snapshot, be aware of other activity in the virtual machine and the likely effect of reverting to that snapshot.

A best practice is to take a 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.

You might not want to take a snapshot in the following circumstances:

■	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.
■	While an application in the virtual machine is sending a transaction to a database on a separate machine. If you revert to that snapshot, especially if you revert after the transaction starts but before it is committed, the transaction fails.