A system includes a volatile storage, a persistent storage, a capacitor-based power supply, and a controller coupled to the capacitor-based power supply. The controller detects interruption of main power, and in response to detecting the interruption of main power, begins backup copying of data from the volatile storage to the persistent storage. After beginning the backup copying of data, the controller checks whether the main power has resumed prior to depletion of the capacitor-based power supply. In response to detecting that main power has resumed prior to depletion of the capacitor-based power supply, the controller resumes operation using content of the volatile storage without restoring data from the persistent storage.