On Wed, Nov 16, 2016 at 02:32:46PM -0500, Daniel J Walsh wrote: > We would like to change the docker container storage to default to > Overlayfs2 in Fedora 26. But we have a problem on Atomic Host and > Fedora Server distributions. > > > Currently docker-storage-setup defaults to devicemapper and is hard > coded to setup a thinpool of 40% of remaining disk. Otherwise it sets > up loopback devices on the root file system. Devicemapper is nice > since it works with thinpools and can automatically expand the storage > if the disk space is getting used up. > > Moving to Overlay, we can more easily use the root file system directly, > which would be fine for Fedora Workstation. We want to preserve the use > of the remaining storage for Overlay on AH and Fedora Server, since > this would give a user flexibility to switch back to using devicemapper > if they had problems with the Overlay driver. And being able to do so basically involves following. - docker-storage-setup creates a logical volume from free space - Creates a filesystem on that logical volume - Mounts that logical volume on the directory which docker is going to use. mount /dev/docker-vg/foo /var/lib/docker/ - Now when docker users overlay2 graph driver, all the images, containers and associated metadata will be stored outside the root filesystem and onto /dev/docker-vg/foo logical volume. > We can not as easily > support the expanding disk for Overlay since we will not use using thinpool. > > We have looked at options to hard code OverlayFS with the defaults, If we always mount /var/lib/docker on on /dev/vg/foo for overlay2 driver this will be a regression w.r.t current behavior. So I would not recommend changing current behavior. I think this should be an opt-in. We are working on provide a config knob to elect this behavior and atomic host and fedora server will have to opt-in somehow. I think it will be easy for atomic host as they already drop something in /etc/sysconfig/docker-storage-setup. Not sure how fedora server variant will do it. Thanks Vivek > or > we could just drop a /etc/sysconfig/docker-storage-setup that specified > Overlay and the percentage of remaining space to use for the > /var/lib/docker device. But what is the best way to set different > defaults for AH, Fedora Server and Fedora Workstation. > > We would like to discuss with you guys about what you would think is > the best way to handle. _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx
