Re: How to recovery a corrupted git repo

From: Axel Freyn <axel-freyn@gmx.de>
Date: Feb 21, 2011, 10:04 UTC
Message-ID: <20110221100454.GM22168@axel>
In-Reply-To: <AANLkTi=W3RckA=e-YwDJzELaEOAa+7P74V-G0G=bQhex@mail.gmail.com>

Hi, On Mon, Feb 21, 2011 at 03:50:09PM +0800, Ping Yin wrote:

Show 13 quoted lines

> I have a corrupted git repo, with "git fsck", it shows
> 
> missing blob b71eb55f2dbc97dafd4a769fc61f346e69a5e0af
> missing blob 282035f3ae964e1e288f352c370be8edd11d3078
> missing tree 3c20f556eecc476e3542cc522d46a62a4461fec6
> missing blob f321b578edeb452358497e832815d6cae6b36886
> missing commit 6d23f5084c975be637f7d748db82116bf84d3872
> 
> And i also have a good backup repo. How can i recover the corrupted
> repo with the backup repo?
> 
> I can do a rsync or fresh "git clone", however, is there any git
> related commands to incrementally do this?

I don't know whether there is a single git command to do it, but you can
copy those 5 objects "by hand": in your backup, you should have a
directory .git/objects, where you have the files
   b7/1eb55f2dbc97dafd4a769fc61f346e69a5e0af
   28/2035f3ae964e1e288f352c370be8edd11d3078
   3c/20f556eecc476e3542cc522d46a62a4461fec6
   f3/21b578edeb452358497e832815d6cae6b36886
   6d/23f5084c975be637f7d748db82116bf84d3872

It should be sufficient to just copy those files into the corrupted repo.

However if you packed the git-files in the backup (e.g. by running "git gc"), those objects might be found in a pack in .git/objects/pack. The easiest ist probably to use git-unpack-objects to unpack the objects, and then copy the 5 missing objects.

Axel

PS: Well, I'm using git and I like it -- but I'm no specialist; so first
do a backup, before you follow my proposal ;-)