Re: [Savannah-hackers-public] FYI, ran "git gc" on all git repositories

[Jim Meyering]

Sylvain Beucler wrote:
> On Fri, Oct 09, 2009 at 04:27:32PM +0200, Jim Meyering wrote:
>> I did the same thing a few months ago.
>> For some it made a big difference: emacs.git went from 1.1GB to 155MB.
>> Active repositories were shrunk to ~20% or even 5% of their original size.
>>
>> This is the script I ran:
>>
>> #!/bin/bash
>> log=$(mktemp /tmp/log-repo-gc-XXXXXX)
>> printf "Run this to see more detail:\ntail -f $log\n"
>> exec >$log
>>
>> cd /vservers/vcs-noshell/srv/git
>>
>> for dir in *.git; do
>>   echo $dir... 1>&2
>>   start_kb=$(du -sk $dir|cut -f1)
>>   printf '%-20s %u KiB->' $dir $start_kb
>>   start_sec=$(date +%s)
>>   git --git-dir=$dir gc
>>   end_sec=$(date +%s)
>>   elapsed=$((end_sec - start_sec))
>>   end_kb=$(du -sk $dir|cut -f1)
>>   percent_saved=$(echo "scale=2; 100 * ($start_kb - $end_kb) / $start_kb"|bc)
>>   printf '%s (saved %s%% in %ss)\n' $end_kb $percent_saved $elapsed
>> done
>
> Cool.  Nice optimization.
>
> I wonder what kind of effects this have though.

It's certainly safe.
I've done this numerous times on savannah, and on other systems,
with no ill effects, other than for those unlucky
enough to have to use git-over-http.

> Possibly HTTP users will have to download a big file (but then
> shouldn't use http ;))

Right on both counts.

> We should ask Petr Baudis from repo.or.cz, I think there's been a
> discussion a year or two ago, and they weren't sure -- or fix git into
> doing it automatically if that's feasible.

One way or another, it's worth automating.