The method of operating a storage system includes executing a storage service providing storage of a volume unit to at least one host device, in which the volume includes a first volume and a second volume. The method includes giving a first priority and a second priority lower than the first priority to the first volume and the second volume, respectively, and recovering meta-data for the first volume having the first priority when the storage service is stopped. The method includes starting the storage service using the recovered meta-data for the first volume, and recovering meta-data for the second volume having the second priority.