In a managed memory subsystem, information associated with the memory subsystem is copied from volatile memory in the memory subsystem to host system memory. The copying can be over a standard interface. Responsive to memory subsystem power up from a powered down state or power loss, the information is copied from the host system memory back to the volatile memory in the memory subsystem, where the information can be used by the memory subsystem to perform memory operations. Transferring information from host system memory to volatile memory in a memory subsystem is faster and more power efficient than transferring the same information from non-volatile memory to volatile memory in the memory subsystem.