On Fri, Nov 06, 2015 at 12:23:29PM -0500, Mikulas Patocka wrote: > I'm also wondering what is this patch useful for. Disks and flash > controllers have their own error detection and correction I think I addressed this earlier. Some storage devices are able to correct bit flips, but don't have enough redundancy to correct larger errors. Using this patch set we can correct N MiB of consecutive corruption anywhere on the partition with the same amount of storage overhead. > Another point - if the read-only system partition is experiencing some > errors, than the read-write partition will probably have errors too On mobile devices, errors in read-only partitions often lead to bricked devices while errors in the read-write parts might only lead to lost cat photos. There are situations where people would prefer to have a working phone even if it fails to store some of their data. > Do you have some real case where such error corrections > increase longevity of some device? Yes, there have been several cases where read-only partition errors have rendered a device unusable. The sheer volume of mobile devices means that even if a tiny fraction of them suffer from such a problem, it's going to affect a large number of people. > But you can take raid5 in read-only mode, put it on several partitions > protected with dm-verity and you get decent error correction I agree. Unfortunately, we don't currently have the luxury of using raid on mobile devices. Sami -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
