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Git Side Benefit: Reducing Disk Usage

A side benefit of switching from Subversion to Git for source control is that Git does not use shadow files and directories to find out what has changed.
I created two checkouts of a svn project — one using traditional svn and one using git (which can actually clone a svn repos — see explanation below).

[~/my-projects]  du -hd 0 \
> berammelse berammelse.git \
> dokboks dokboks.git       \
> intrastat intrastat.git   \
> kompetenceregister k2.git \
> ourpeople ourpeople.git   \
> let0004 let0004.git

43M     berammelse
38M     berammelse.git
63M     dokboks
11M     dokboks.git
53M     intrastat
34M     intrastat.git
144M    kompetenceregister
47M     kompetenceregister.git
118M    ourpeople
151M    ourpeople.git
163M    let0004
98M     let0004.git

For any project I tried this, Git uses significantly less disk space. It’s just a side effect, I know. But more important: The git version has all the logfile history offline and that makes rolling forward/back much faster :)
FYI i’m using my version of Dr. Nic’s “gitify” command that wraps a “git svn” command. This way I can use git locally and then re-commit into svn when done.

#!/usr/bin/env ruby -wKU
# command from
# http://drnicwilliams.com/2007/11/22/going-offline-without-your-favourite-subversion-repository/
# Install with
# sudo port install git-core +svn

# get svn info location
svnurl = `svn info | grep "^URL:"`.gsub(‘URL: ‘,”).chomp

# project = basename
project = File.basename(Dir.pwd)

puts cmd = "git svn clone #{svnurl} ../#{project}.git"

`#{cmd}`

puts "(‘git svn rebase’ merges changes from svn.\n ‘git svn dcommit’ updates svn with your git commits)"

This entry was posted by Jesper Rønn-Jensen on Saturday, January 17th, 2009 at 14:28 (UTC) and is filed under Code. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

2 Responses to “Git Side Benefit: Reducing Disk Usage”

  1. Jeet Says:
    January 26th, 2009 at 10:46 (UTC)

    I am not entirely sure about git reducing the disk usage, since it has to keep ‘whole’ copies of the commits, I am inclined to think that total size required by a well used git repository would be higher than svn/cvs repository that will only keep differences.

    Might try something locally before I can conclude.. but yeah, I have switched to git already :))

  2. Jesper Rønn-Jensen Says:
    March 9th, 2009 at 10:08 (UTC)

    @Jeet i follow your thoughts but the repositories I tested with above actually shows a disk usage reduction.

    The biggest SVN repository above had more than 16,000 commits and the Git version was 40% smaller even though it contained the entire project history.

    So even though that the svn repositories here are only snapshots in time (the history remains on the server), there is a significant difference.

    BTW, the Git repos also only contains differences between each revision.

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