[Nix-dev] aufs & kernel 2.6.28.9

[Tony White]

2009/4/14 Eelco Dolstra <e.dolstra at tudelft.nl>:
> Hi,
>
> Tony White wrote:
>
>> I trying to build a rescue cd with 2.6.28.9 so that I can try to make
>> ext4fs
>
> Ah good, it would be nice to update to 2.6.28 :-)
>
>> So I can see it's an aufs problem, I'm guessing it could do with a
>> newer version. However I goto download :
>>
>> http://nixos.org/tarballs/aufs-20080508.tar.bz2
>>
>> To inspect the archive layout and it's a different to the layout to :
>>
>> http://sourceforge.net/project/downloading.php?group_id=167503&filename=aufs2-base5.tar.bz2
>>
>> Which is the latest current stable version, So my questions are :
>>
>> Is aufs absolutely a requirement of the rescue cd? I know I can
>> disable it to save time but is it worth it?
>
> Yes, it's required.  AUFS is used to provide a writable root file system.  The
> CD won't boot without it.
>
>> Is editing the expression to use the sourceforge archive the correct
>> method of resolution?
>> Is the aufs-20080508.tar.bz2 the same thing, Just a slightly different?
>
> aufs-20080508.tar.bz2 is an export of the AUFS CVS repository.  Also, it's for
> aufs1 - aufs2 is the next generation implementation.  I don't know how stable
> aufs2 is.
>
> We currently build aufs1 as a external module.  However, the aufs2 release
> (aufs2-base5) only contains a patch to the kernel source tree, and apparently
> doesn't support building as an external module (according to
> http://aufs.sourceforge.net/README.aufs2).  So we would have to build one
> aufs-utils package, and the module itself as a kernel patch.
>
> --
> Eelco Dolstra | http://www.st.ewi.tudelft.nl/~dolstra/
>

Thanks Eelco,
Yes, I did a little further exploration and realized that yes aufs is
a basic requirement of the live cd and that the archive on the NixOS
server is indeed a cvs snapshot, Thanks for confirming that. :)

Now I can see that it's going to be quite an undertaking for myself to
attempt to create a nix package that does as you say, Patch the kernel
at build time instead of a separate module.
I seem to remember that unionfs is in mainline now but can't be sure.
An option to use unionfs instead on the live CD (Although I am aware
of the merits of using aufs) Would be quite a slick option.

I'll investigate creating a seperate kernel simply for the live CD
instead of a seperate package that patches the kernel at build time
because aufs isn't something I'd need normally.
Looks like I'll have my hands full at the weekend. :)

Thanks again,

Tony