[[!meta title="Splitting a git-annex repository"]]

Note: this is the reverse of [[migrating two seperate disconnected directories to git annex]].

I have a [git annex](https://git-annex.branchable.com/) repo for all my media
that has grown to 57866 files and git operations are getting slow, especially
on external spinning hard drives, so I decided to split it into separate
repositories.

This is how I did it, with some help from `#git-annex`. Suppose the old big repo is at `~/oldrepo`:

```
# Create a new repo for photos only
mkdir ~/photos
cd photos
git init
git annex init laptop

# Hardlink all the annexed data from the old repo
cp -rl ~/oldrepo/.git/annex/objects .git/annex/

# Regenerate the git annex metadata
git annex fsck --fast

# Also split the repo on the usb key
cd /media/usbkey
git clone ~/photos
cd photos
git annex init usbkey
cp -rl ../oldrepo/.git/annex/objects .git/annex/
git annex fsck --fast

# Connect the annexes as remotes of each other
git remote add laptop ~/photos
cd ~/photos
git remote add usbkey /media/usbkey
```

At this point, I went through all repos doing standard cleanup:

```
# Remove unneeded hard links
git annex unused
git annex dropunused --force 1-12345

# Sync
git annex sync
```

To make sure nothing is missing, I used `git annex find --not --in=here`
to see if, for example, the usbkey that should have everything could be missing
some thing.

Update: Antoine Beaupré pointed me to
[this tip about Repositories with large number of files](http://git-annex.branchable.com/tips/Repositories_with_large_number_of_files/)
which I will try next time one of my repositories grows enough to hit a performance issue.

> This document was originally written by [Enrico Zini](http://www.enricozini.org/blog/2017/debian/splitting-a-git-annex-repository/) and added to this wiki by [[anarcat]].
