On Thu, Oct 11, 2018 at 01:38:34PM -0500, Eric Sandeen wrote: > > The different behavior between filesystems was confusing customers so > > we had to align them, then the question was which default to pick. > > Honestly, we came to the decision to bring ext4 in line with the xfs > > behavior because we thought that would be easier than the alternative. > > Dave and Christoph made repeated arguments that DAX is just a hidden > > performance optimization that no application should rely on, so we > > went the path of least resistance and changed the ext4 default. > > Ok, well, I guess we'd better reconcile "it's a hidden performance hint" > with "if the administrator asked they must receive..." before making this > change... cc: hch for bonus input. I don't really care too mouch on the mount options, the important bit was the application behavior. I fully agree with Dan that we should have the same behavior for every file system, though.