Remove file from git repository (history)

Question

(solved, see bottom of the question body)
Looking for this for a long time now, what I have till now is:

• http://dound.com/2009/04/git-forever-remove-files-or-folders-from-history/ and
• http://progit.org/book/ch9-7.html

Pretty much the same method, but both of them leave objects in pack files... Stuck.
What I tried:

git filter-branch --index-filter 'git rm --cached --ignore-unmatch file_name'
rm -Rf .git/refs/original
rm -Rf .git/logs/
git gc

Still have files in the pack, and this is how I know it:

git verify-pack -v .git/objects/pack/pack-3f8c0...bb.idx | sort -k 3 -n | tail -3

And this:

git filter-branch --index-filter "git rm -rf --cached --ignore-unmatch file_name" HEAD
rm -rf .git/refs/original/ && git reflog expire --all &&  git gc --aggressive --prune

The same...

Tried git clone trick, it removed some of the files (~3000 of them) but the largest files are still there...

I have some large legacy files in the repository, ~200M, and I really don't want them there... And I don't want to reset the repository to 0 :(

SOLUTION: This is the shortest way to get rid of the files:

1. check .git/packed-refs - my problem was that I had there a refs/remotes/origin/master line for a remote repository, delete it, otherwise git won't remove those files
2. (optional) git verify-pack -v .git/objects/pack/#{pack-name}.idx | sort -k 3 -n | tail -5 - to check for the largest files
3. (optional) git rev-list --objects --all | grep a0d770a97ff0fac0be1d777b32cc67fe69eb9a98 - to check what are those files
4. git filter-branch --index-filter 'git rm --cached --ignore-unmatch file_names' - to remove a file from all revisions
5. rm -rf .git/refs/original/ - to remove git's backup
6. git reflog expire --all --expire='0 days' - to expire all the loose objects
7. git fsck --full --unreachable - to check if there are any loose objects
8. git repack -A -d - repacking
9. git prune - to finally remove those objects

Answer 1

I can't say for sure without access to your repository data, but I believe there are probably one or more packed refs still referencing old commits from before you ran git filter-branch. This would explain why git fsck --full --unreachable doesn't call the large blob an unreachable object, even though you've expired your reflog and removed the original (unpacked) refs.

Here's what I'd do (after git filter-branch and git gc have been done):

1) Make sure original refs are gone:

rm -rf .git/refs/original

2) Expire all reflog entries:

git reflog expire --all --expire='0 days'

3) Check for old packed refs

This could potentially be tricky, depending on how many packed refs you have. I don't know of any Git commands that automate this, so I think you'll have to do this manually. Make a backup of .git/packed-refs. Now edit .git/packed-refs. Check for old refs (in particular, see if it packed any of the refs from .git/refs/original). If you find any old ones that don't need to be there, delete them (remove the line for that ref).

After you finish cleaning up the packed-refs file, see if git fsck notices the unreachable objects:

git fsck --full --unreachable

If that worked, and git fsck now reports your large blob as unreachable, you can move on to the next step.

4) Repack your packed archive(s)

git repack -A -d

This will ensure that the unreachable objects get unpacked and stay unpacked.

5) Prune loose (unreachable) objects

git prune

And that should do it. Git really should have a better way to manage packed refs. Maybe there is a better way that I don't know about. In the absence of a better way, manual editing of the packed-refs file might be the only way to go.