[RFC] AUFS disabled for 12.04

[Mike Mestnik]

See bug number 1007089

overlayfs alters /proc/self/exe link(s), making result a dead link.

Test script, from #40:
(
set -e
mkdir -p /mnt/test /tmp/usr
mount none /mnt/test -t overlayfs -o lowerdir=/usr,upperdir=/tmp/usr
/mnt/test/bin/tail -f /dev/null&
ls -lart /proc/$!/exe
kill $!
umount /mnt/test
rmdir /mnt/test /tmp/usr
)
# If a red broken link to/bin/tail is printed then the bug exists. If
the link points to /mnt/test/bin/tail then there is no bug in the
currently running kernel.
On 02/29/12 10:57, Leann Ogasawara wrote:
> Hi All,
> 
> Early in the Precise Pangolin 12.04 development cycle, we disabled
> support for AUFS in the kernel.  This decision was made at UDS.  The
> reasoning behind this decision included:
> 
>       * AUFS is not upstream.  Despite previous efforts from it's
>         maintainer, it does not appear it will ever land upstream.
>       * AUFS is a maintenance burden for the Ubuntu Kernel Team due to
>         the fact that it is not upstream.
>       * Support for OverlayFS has been available since Oneiric.  We have
>         been encouraging migration to OverlayFS. The installer has
>         already transitioned to using OverlayFS (which was done in
>         Oneiric).
> 
> We've noted the disablement of AUFS in every Technical Overview for each
> 12.04 milestone.  However, we felt it was also necessary to send a
> widespread notification.
> 
> For anyone struggling with the dropped support of AUFS, we would like to
> hear from you.  We'd be particularly interested in specific use case
> scenarios where OverlayFS is not meeting the needs/requirements
> previously met by AUFS.  We are already aware of some inotify issues
> with OverlayFS [1].  We are curious if there are any other specific
> cases where people are experiencing issues with OverlayFS.  We'd like to
> gather any compelling evidence to support the requests to re-enable
> AUFS.
> 
> Thanks,
> Leann Ogasawara
> 
> [1] https://lkml.org/lkml/2012/2/28/223
> 
>