[Savannah-hackers-public] Re: [sr #107505] Please reduce gnash git repo size

[Sylvain Beucler]

Hi,

On Sun, Oct 24, 2010 at 11:26:09PM +0200, Jim Meyering wrote:
> Sylvain Beucler wrote:
> > Jim,
> >
> > Can you have a look at this?
> >
> > The gnash repo can be packed from 760M (gc) to 60M (gc --aggressive).
> 
> Nice! (in a way ;-)
> 
> > Does that sound normal?  Is there a risk to lose data with it?
> 
> It is to be expected, if no one has ever run
> "git gc --aggressive" or an equivalent on this repository before.
> 
> > If not, should we plan to do it on other repo too?
> 
> Yes, I think so.  "git gc" documentation suggests to run it
> "every few hundred change-sets or so".
> 
> > On Sun, Oct 24, 2010 at 08:14:03PM +0000, Sylvain Beucler wrote:
> >>
> >> Follow-up Comment #2, sr #107505 (project administration):
> >>
> >> Wow, it's down to 60M after 20mn.
> >> I'll check with Jim to have an opinion on doing it on the real repo.
> 
> As far as I know, there is no risk of data loss.
> I think of "git gc" as coalescing into a new "pack" any free objects,
> and compressing that resulting new pack.
> On the other hand, with --aggressive, it examines all objects
> (including those in previously coalesced packs) and does a global
> search for common/compressible things.
> 
> Thus, if you have many separately-packed changes that would have
> been better compressed if they'd ended up in the same pack,
> --aggressive will yield significant benefit.

Thanks for the info.

Do you know about concurrency?  I.e. need we make the repo read-only
for developers when we're doing such a repack?

-- 
Sylvain