Users may now stop servers they are not currently using but still retain them in their list of servers. This is referred to as shelving. A shelved server can be restarted using its same data, configuration, and identity at a point in the future. While a server is shelved, hypervisors are able to reclaim the resources that were used by that server and use it for running other servers if needed.
Users would like the ability to stop servers when they do not need them, but retain it in their list of servers and retain all data and resources associated with it. If an instance is stopped for an extended period of time, an operator may wish to move that instance off of the hypervisor in order to minimize resource usage.