On Wed, Aug 16, 2017 at 05:13:44PM +0200, Pawel Baldysiak wrote: > Current Partial Parity Log implementation allows only single PPL to be > written to particular member drive. In such case PPL entry is > overwritten by every write as it's stored at the same sector of a drive. > Such approach is suboptimal for SSD drives as it leads to increased > write amplification factor due to write-after-write limitations. > > This patchset changes the implementation by extending PPL area to 1MB. > PPL is not stored at fixed location but multiple PPLs are written in a > circular buffer. There is at most one valid PPL at any time (latest > one). Recovery algorithm stays the same. The main benefits of this > approach are increased drive lifespan and in some cases improved > performance. The patches look good. Is this in intel RST standard? I didn't get the point why this is helpful though. You mentioned reduce write amplification. Why does this reduce write amplification? As far as I know, SSD never does in-place write, write to the same sector or different sector has no difference. Thanks, Shaohua -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
