DATA STORAGE DEVICE AND METHOD FOR USING SECONDARY NON-VOLATILE MEMORY FOR TEMPORARY METADATA STORAGE

A data storage device is disclosed comprising a volatile memory, a primary and a first secondary non-volatile memory (NVM), and control circuitry coupled to the volatile memory and the primary and first secondary NVM and configured to (a) write metadata and user data associated with a host write command to the volatile memory; (b) write the user data to the primary NVM; (c) continue to write metadata associated with each of one or more host write commands to the volatile memory, and when a first condition is met, write metadata that has accumulated in the volatile memory to the first secondary NVM; and (d) repeat (c), and when a second condition is met, then write at least a portion of the metadata that has accumulated in the first secondary NVM or the volatile memory to the primary NVM.