On Wed, Sep 14, 2016 at 2:45 PM, Jason Brooks <jbrooks@xxxxxxxxxx> wrote: > On Wed, Sep 14, 2016 at 12:14 PM, Dusty Mabe <dusty@xxxxxxxxxxxxx> wrote: >> >> In the cloud meeting today I brought up overlayfs and F25. After >> discussing with the engineers closer to the technology they recommend >> waiting to move to overlayfs as the default in F26. >> >> I think this will work well because it will give us some time to allow >> people to "try" overlayfs in F25 (we should provide good docs on this) >> and then give us feedback before we go with it as default in F26. If >> the feedback is bad then maybe we wouldn't even go with it in F26, but >> hopefully that won't be the case. >> >> Thoughts? > > Sounds good to me. I'm uncertain if this is current or needs an update: Evaluate overlayfs with docker https://github.com/kubernetes/kubernetes/issues/15867 If the way forward is a non-duplicating cache then I see a major advantage gone. But that alone isn't enough to promote something else, I'd just say, hedge your bets. Pretty much all the reasons why CoreOS switched from Btrfs to overlay have been fixed, although there's a asstrometric ton of enospc rework landing in kernel 4.8 [1] that will need time to shake out, and if anyone's able to break it, one of the best ways of getting it fixed and avoiding regressions is to come up with an xfstests [2] for it to be cleanly reproduced. The Facebook devs consistently report finding hardware (even enterprise stuff that they use) doing batshit things that Btrfs catches and corrects that other filesystems aren't seeing. And then on the slow downs mainly due to fragmentation when creating and destroying many snapshots over a short period of time, this probably could be mitigated with garbage collection optimization, and I've had some ideas about that if anyone wants to futz around with it. The more conservative change is probably XFS + overlayfs though, since now XFS checksums fs metadata and the journal, which helps catch problems before they get worse. [1] http://www.spinics.net/lists/linux-btrfs/msg53410.html [2] semi random example http://oss.sgi.com/cgi-bin/gitweb.cgi?p=xfs/cmds/xfstests.git;a=blob;f=tests/btrfs/060 -- Chris Murphy _______________________________________________ cloud mailing list cloud@xxxxxxxxxxxxxxxxxxxxxxx https://lists.fedoraproject.org/admin/lists/cloud@xxxxxxxxxxxxxxxxxxxxxxx
