Your first two commands work fine to create a base bundle. However, your second group of commands won't do the right thing. You do want the git fetch (--all is needed only if you have multiple remotes), but you want the newly created differential bundle to be done with "negative refspecs" for every ref that was a positive refspec in the previous bundle. That is:
git bundle create diff.bundle $(git rev-parse HEAD)..HEAD --all
is clearly wrong for two reasons:
- The inner
git rev-parse HEAD uses the current HEAD, which may not be correct; - If the previous bundle (initial or previous differential) used
refs/heads/br1, refs/heads/br2, refs/tags/t1, refs/remotes/origin/r1, and refs/remotes/origin/r2 as its positive refspecs via --all, you need negative refspecs that will produce each hash ID from all of the positive refspecs.
The easiest way to fix both of these is to:
- have the initial sequence end with
git rev-parse --all with output saved somewhere; - for creating a new differential bundle, use
^$hash for each hash ID listed in the saved output from the last save; - after creating the new differential bundle, use
git rev-parse --all again to get the positive refspec hash IDs.
So you'll end up with something along these lines:
git clone --mirror https://github.com/me/myrepo git bundle create $HOME/b/base.bundle --all git rev-list --all > $HOME/b/hashes
followed by:
cd myrepo git fetch # --all if needed, but per the above there's just one remote git bundle create $HOME/b/diff.bundle $(sed s/^/^/ < $HOME/b/hashes) --all git rev-list --all > $HOME/b/hashes
Warning: this is entirely untested. I'm also assuming that each diff.bundle is an increment to the previous diff.bundle here, i.e., these each need to be saved separately.
(You're probably best off using real backup software anyway, but this is likely to work.)
