A non-mechanical persistent storage is provided for a mechanical storage device. The operating system instructs the mechanical storage device to cache ranges of data stored in the mechanical storage device in the non-mechanical persistent storage. The mechanical storage device then transfers the data to the non-mechanical persistent storage. When the operating system makes a write to a range that is tracked in the non-mechanical persistent storage, the data is written to the mechanical storage and mirrored to the non-mechanical persistent storage. When the operating system makes a read to a range that is tracked in the non-mechanical persistent storage, such as when the system is in startup, the data is read from the non-mechanical persistent cache.