Split large Git repository into many smaller ones

Question

After successfully converting an SVN repository to Git, I now have a very large Git repository that I want to break down into multiple smaller repositories and maintain hist

Answer 1

You could use git filter-branch --index-filter with git rm --cached to delete the unwanted directories from clones/copies of your original repository.

For example:

trim_repo() { : trim_repo src dst dir-to-trim-out...
  : uses printf %q: needs bash, zsh, or maybe ksh
  git clone "$1" "$2" &&
  (
    cd "$2" &&
    shift 2 &&

    : mirror original branches &&
    git checkout HEAD~0 2>/dev/null &&
    d=$(printf ' %q' "$@") &&
    git for-each-ref --shell --format='
      o=%(refname:short) b=${o#origin/} &&
      if test -n "$b" && test "$b" != HEAD; then 
        git branch --force --no-track "$b" "$o"
      fi
    ' refs/remotes/origin/ | sh -e &&
    git checkout - &&
    git remote rm origin &&

    : do the filtering &&
    git filter-branch \
      --index-filter 'git rm --ignore-unmatch --cached -r -- '"$d" \
      --tag-name-filter cat \
      --prune-empty \
      -- --all
  )
}
trim_repo MyHugeRepo MyABRepo DIR_1 DIR_2
trim_repo MyHugeRepo My12Repo DIR_A DIR_B

You will need to manually delete each repository’s unneeded branches or tags (e.g. if you had a feature-x-for-AB branch, then you probably want to delete that from the “12” repository).