Re: [PATCH] git-repack question

From: Linus Torvalds <torvalds@osdl.org>
Date: Feb 17, 2006, 22:20 UTC
Message-ID: <Pine.LNX.4.64.0602171414220.916@g5.osdl.org>
In-Reply-To: <20060217213824.5848.qmail@science.horizon.com>

On Fri, 17 Feb 2006, linux@horizon.com wrote:

>
> I'm trying to imagine when you'd want to run git-repack without the -d
> option, or without running git-prune-packed afterwards.
> (Isn't the idea behind packs to save space?)

Normally you'd always run git-prune-packed.

The reason it doesn't do that is simply being anally careful, and because conceptually the pruning phase is totally independent.

For example, in an environment that mirrors out git repositories by rsync, it can make sense to wait with pruning until the mirror cycle has finished, so that all mirrors always have all the objects.

(I don't do it for the kernel, because (a) I'm a lazy bastard, (b) I'm so confused that I sometimes forget my own name, much less to prune things a day after I've repacked them and (c) I don't care that much about rsync anyway, since you can't avoid some of the _other_ races).

As to whether you'd normally run "-d" - usually you'd run it whenever you pair it up with "-a". When you do an incremental re-pack, "-d" won't do anything anyway.

Again, it might make sense to not delete the old packs when repacking everything in a rsync'ing environment - or even in a shared repository, where removing a pack-file could race with somebody else working on it.

Basically, the default ends up being to never remove any objects at all, simply because that's the _safe_ thing to do.

In practice, I personally always do

	git repack -a -d
	git prune-packed

together, because the full repack isn't _that_ expensive for me (I tend to have lots of cpu power), and because I can't be bothered to worry too much about rsync and there are never any other users working on my git trees.

		Linus