https://nalar.dev/tags/wear-leveling/ Recent content in Wear Leveling on Nalar Hugo en-us Mon, 01 Jan 0001 00:00:00 +0000 https://nalar.dev/ssd-overprovisioning-gives-flash-controllers-spare-working-space/ Wed, 16 Sep 2026 00:00:00 +0700 https://nalar.dev/ssd-overprovisioning-gives-flash-controllers-spare-working-space/ <p>Solid-state drives expose less capacity to the host than the total flash available inside many devices. Part of that difference can serve as overprovisioned space: flash capacity the controller can use internally but the operating system cannot address as normal storage.</p> <p>That spare area is useful because NAND flash cannot overwrite existing data in place. Pages are programmed in relatively small units, while erasure happens in larger blocks. Rewriting a logical sector usually places the new data in another physical page and marks the old page invalid. Over time, blocks become mixtures of valid and invalid pages.</p>