Re: Problem making large .deb files

[Guillem Jover <guillem@debian.org>]

Hi!

On Mon, 2016-05-16 at 11:42:02 -0600, Nicholas Clark wrote:
> I ran into an interesting limitation of the .deb package format today. I
> work at an electronics design company, where I maintain my company's build
> servers. We use some vendor-supplied toolchains that have very large
> installations (~30GB uncompressed).
> 
> I've been trying to repackage these toolchains so that I can control their
> configuration and deployment, and I hit something interesting. Since .deb
> files are built using 'ar' at the top-level, they can't hold any single
> files that are larger than 9.99GB, which appears to be a fundamental
> limitation of the ar format.

Yes, and a known one:

  <https://wiki.debian.org/Teams/Dpkg/TimeTravelFixes>

also mentioned in the format spec:

  <http://man7.org/linux/man-pages/man5/deb.5.html>a

I've now added locally the other limitation coming from each tar entry
size inside a tar archive, which is 8 GiB per tar entry (uncompressed).

> Is there anything I can do to get around this? If not would it be possible
> to make some tweaks to the .deb file format in a future release? Maybe
> replacing 'ar' with tar, or allowing multiple data archive files in the
> package?

There are few workarounds. One is to use stronger compression so that
the ar members are smaller and fit better. The other might be to split
the contents in several binary packages, so that you don't reach the
limit.

Thanks,
Guillem