docker run fail on Ubuntu 13.04 and btrfs

[vieux]

Mount aufs fail, dmesg output:

[14347.704048] aufs au_xino_create:720:docker[18512]: xino doesn't support /tmp/.aufs.xino(btrfs)

/cc @dysinger

[shykes]

FYI this is caused by the fact that btrfs cannot store aufs xino files. By default aufs tries to store them in the alongside the rw layer. If that fails, it tries to store them in /tmp/.aufs.xino. In this case /tmp is also mounted as btrfs, so it fails as well.

One easy workaround is to mount /tmp as something other than btrfs - for example tmpfs.

@vieux is suggesting the approach of using /dev/shm, which unlike /tmp is pretty much guaranteed to use tmpfs, thus not suffering from the limitations of btrfs.

See http://comments.gmane.org/gmane.linux.file-systems.aufs.user/2437 and http://aufs.sourceforge.net/aufs3/man.html#External Inode Number Bitmap, Translation Table and Generation Table (xino)