On Mon, Aug 14, 2017 at 8:23 AM, Goffredo Baroncelli <[email protected]> wrote:
> Form a theoretical point of view, if you have a "PURE" COW file-system, you > don't need a journal. Unfortunately a RAID5/6 stripe update is a RMW cycle, > so you need a journal to keep it in sync. The same is true for the NOCOW file > (and their checksums) > I'm pretty sure the raid56 rmw is in memory only, I don't think we have a case where a stripe is getting partial writes (a block in a stripe is being overwritten). Partial stripe updates with rmw *on disk* would mean Btrfs raid56 is not CoW. -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
