A solid-state mass storage device and method for its operation that includes performing preemptive scrubbing of data during offline periods or disconnects from a host system to which the mass storage device is attached. The device includes a system interface adapted to connect the drive to a host system, at least one nonvolatile memory device, controller means through which data pass when being written to and read from the memory device, a volatile memory cache, a system logic device, and an integrated power source for powering the drive. The system logic device is configured to operate when the drive is not functionally connected to a host system, execute copy commands without accessing a host system, and prioritize preemptive scrubbing of addresses in the memory device on the basis of risk of data loss based on one or more parameters logged by the internal system logic device.