A storage device includes a nonvolatile memory, and a controller configured to perform, in response to commands from the host device, a read operation and a write operation on the nonvolatile memory. The controller divides a logical address space of the storage device into a plurality of subspaces and manages a priority value for each of the subspaces, the priority values of the subspaces determining an order for setting up the subspaces upon start-up of the storage device.