git-filter-branch can be used to get rid of a subset of files,
usually with some combination of --index-filter and
--subdirectory-filter. People expect the resulting repository to
be smaller than the original, but you need a few more steps to
actually make it smaller, because Git tries hard not to lose your
objects until you tell it to. First make sure that:
• You really removed all variants of a filename, if a blob was
moved over its lifetime. git log --name-only --follow --all
-- filename can help you find renames.
• You really filtered all refs: use --tag-name-filter cat --
--all when calling git-filter-branch.
Then there are two ways to get a smaller repository. A safer way
is to clone, that keeps your original intact.
• Clone it with git clone file:///path/to/repo. The clone will
not have the removed objects. See git-clone(1). (Note that
cloning with a plain path just hardlinks everything!)
If you really don't want to clone it, for whatever reasons, check
the following points instead (in this order). This is a very
destructive approach, so make a backup or go back to cloning it.
You have been warned.
• Remove the original refs backed up by git-filter-branch: say
git for-each-ref --format="%(refname)" refs/original/ | xargs
-n 1 git update-ref -d.
• Expire all reflogs with git reflog expire --expire=now --all.
• Garbage collect all unreferenced objects with git gc
--prune=now (or if your git-gc is not new enough to support
arguments to --prune, use git repack -ad; git prune instead).
