docker.io (1.11.2~ds1-1) unstable; urgency=medium

  As of src:linux 4.0+ (specifically, >= 3.18-1~exp1), AUFS support is no longer
  included in official Debian-compiled kernels.  What this means to Docker users
  is that if your existing images are stored within the "AUFS" graph driver that
  once you update your kernel, your images (and containers) will become
  inaccessible (due to the kernel not having the necessary aufs modules to mount
  them).  To recover from this, there are a couple options (detailed below).

  1. Use the included nuke script to blow away your existing "/var/lib/docker"
     contents and start fresh with Linux 4.0+:

       service docker stop
       /usr/share/docker.io/contrib/nuke-graph-directory.sh /var/lib/docker
       service docker start

  2. Use "docker save" (see "docker help save" for usage) before booting 4.0+ to
     preserve your images on-disk as tar files, then follow the nuke step from
     the previous option followed by using "docker load" to re-load your images.

  3. Update to src:linux >= 4.1.1-1~exp1 ("aufs: Apply patches to enable
     building aufs out-of-tree"), and then compile the aufs modules out-of-tree
     (a package for doing this module compilation automatically doesn't yet
     exist at the time of this writing, but might in the future).

 -- Tianon Gravi <tianon@debian.org>  Tue, 01 Dec 2015 01:02:44 -0800