Storage device and operating method thereof

An operating method of a storage device which includes a first nonvolatile memory device, a second nonvolatile memory device, and a storage controller configured to control the first nonvolatile memory device and the second nonvolatile memory device, the method comprising:

• detecting sudden power-off;
• suspending an operation being performed in the first nonvolatile memory device, in response to the detected sudden power-off;
• writing suspension information about the suspended operation into the second nonvolatile memory device;
• and
• performing a block management operation on the first nonvolatile memory device based on the suspension information written into the second nonvolatile memory device, in power-up after the sudden power-off,
• wherein the storage device further includes a power management circuit configured to supply a power to the first nonvolatile memory device, the second nonvolatile memory device, and the storage controller, to detect sudden power-off associated with at least one of the first nonvolatile memory device, the second nonvolatile memory device, and the storage controller, and to provide a sudden power-off signal to the storage controller.