In a method of operating a storage device, first information associated with operation of the storage device is received from a host device. Second information internally generated based on write requests, read requests, and operation of the storage device is received. Program commands and read commands are transmitted to nonvolatile memories. Suspension commands are transmitted to at least one of nonvolatile memories. The suspension commands are generated based on the first and second information and are used to temporarily stop program operations performed based on the program commands. The number and timing of transmitting the suspension commands are controlled based on the first and second information. In response to changing at least one of the write requests and the read requests, the number and timing of transmitting the suspension commands are adaptively changed.