From: Nicolas Pitre <nico@fluxnic.net>
Date: Tue, 12 Jun 2012 19:35:17 GMT
Subject: Re: Keeping unreachable objects in a separate pack instead of loose?
Message-ID: <alpine.LFD.2.02.1206121533370.23555@xanadu.home>
In-Reply-To: <20120612191929.GA12161@thunk.org>

On Tue, 12 Jun 2012, Ted Ts'o wrote:

> On Tue, Jun 12, 2012 at 03:15:46PM -0400, Nicolas Pitre wrote:
> > > But the old packs are huge; in my case, a full set of packs was around
> > > 16 megabytes.  Right now, git gc *increased* my disk usage by 4.5
> > > megabytes.  If we don't delete the old backs, then git gc would
> > > increase disk usage by 16 megabytes --- which is far, far worse.
> > > 
> > > Writing a 244k cruft pack is a soooooo much preferable.
> > 
> > But as you might have noticed, there are a bunch of semantic problems 
> > with that as well.
> 
> I've proposed something (explicitly labelled cruft packs) which is no
> worse than before.  The one potential problem is that objects in the
> cruft pack might have their lifespan extended by two weeks (or
> whatever the expire timeout might be), but Peff has agreed that it's
> simple enough to ignore that, since the benefits far outweigh the
> potential that some objects in cruft packs will get to live a bit
> longer.
> 
> The race condition you've pointed out exists today, with the git prune
> racing against the git fetch.

Yes, however that race is trivial to fix when loose objects are used.


Nicolas