Hi Urs, Your plan to change the SATA cable seems wise - your various error rates are higher than I have normally seen.
Also worth bearing in mind that Linux MD RAID 1 will satisfy all read IO for a given operation from one device in the mirror. If you have processes that do occasional big reads then by chance those can end up being served by the same device leading to a big disparity in per-device LBAs read. You can do RAID-10 (even on 2 or 3 devices) which will stripe data at the chunk size resulting in even a single read operation being striped across multiple devices, though overall this may not be more performant than RAID-1, especially if your devices were non-rotational. You would have to measure. I don't know about the write overhead you are seeing. Cheers, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting
