Bug#773868: live-boot: Does not include overlayfs support in initramfs, due to wrong kernel module naming

[Michal Suchanek <hramrach@gmail.com>]

On 24 December 2014 at 13:41,  <intrigeri@debian.org> wrote:
> Package: live-boot
> Version: 4.0.2-1
> Severity: normal
> Tags: patch
>
> Hi,
>
> backend/initramfs-tools/live.hook tries to include the "overlayfs"
> kernel module in the initramfs. However, that module is called
> "overlay", so it's never included, and then booting with the
> union=overlayfs parameter can't work out-of-the-box.
>
> I've fixed this in the bugfix/overlay-module branch at
> https://git-tails.immerda.ch/live-boot => please review and merge :)
>
> Once Linux 3.18+ reaches sid, with only overlayfs support and no more
> aufs, Debian Live systems who want/need to ship a kernel newer than
> the one from Jessie will need to use overlayfs, so it would be good if
> live-boot in Jessie supported it. I'll let the maintainer judge.

Hello,

regarding the upcoming overlayfs support I have two questions.

1) is it worthwhile to have support both for the old overlayfs.ko and
the new overlay.ko?

I am not aware of anyone except myself who was using old kernels
patched with overlayfs which produce overlayfs.ko and I am aware of
the change now so this might be a non-issue.

2) what is the reasoning behind renaming /cow to /overlay?

It the function of /overlay so different that existing tools using
/cow cannot work with it when overlayfs is used? I think many tools
work with the directory by just packing up the content and do not
really care about the details of the union so a needless change in the
directory name would needlessly require updating tools. I do not use
these directories for anything myself so I would not know.

Thanks

Michal