What is saved state?
Saved state, in a virtualization context, is a way to store the current state of a virtual machine so that is possible to return to that state quickly when desired. The effect is similar to hibernation on a laptop. Saving the virtual machine state means that resources are freed for the host machine until the state is resumed.
To begin a saved state, all input/output (I/O) processes are stopped at the same time. The virtual machine state, including data in memory and system state, is copied to a temporary file on the server. To reactivate the virtual machine, the file contents are copied back into the VM's virtual memory space and I/O processes are resumed.