Re: Keeping unreachable objects in a separate pack instead of loose?

[Hallvard Breien Furuseth <h.b.furuseth@usit.uio.no>]

 On Mon, 11 Jun 2012 14:34:14 -0400, Jeff King <peff@peff.net> wrote:
> On Mon, Jun 11, 2012 at 01:27:32PM -0400, Ted Ts'o wrote:
>> So depending on how you would want to do the comparison, probably 
>> the
>> fairest thing to say is that I had a total "good" packs totally 
>> about
>> 16 megs, and the loose cruft objects was an additional 4.5 
>> megabytes.
>
> OK, so that 4.5 is at least a respectable percentage of the total 
> repo
> size. I suspect it may be worse for small repos in that sense, (...)

 'git gc' gave a 3100% increase with my example:

     $ git clone --bare --branch linux-overhaul-20010122 \
         git://git.savannah.gnu.org/config.git
     $ cd config.git/
     $ git tag -d `git tag`; git branch -D master
     $ du -s objects
     624     objects
     $ git gc
     $ du -s objects
     19840   objects

 Basically: Clone/fetch a repo, keep a small part of it, drop the
 rest, and gc.  Gc explodes all the objects you no longer want.

 This hits you hard if your small project tracks a big one, and
 later ceases doing so.  Maybe your project is to convert a small
 part of the remote into a library, or you're just tracking a few
 files from the remote - e.g. from the GNU Config repo.

 Not something one does every day, but it does happen.
 Tweaks to expiration time etc do not help here.

 Hallvard