I have a large annex (~200k files) on a server with a thin checkout on my laptop.

The scenario I was trying to achieve is to by default have:

- All files always present on the server
- Only files added locally/pulled manually on the laptop

It seems this can be achieved by setting preferred content to `present` on the laptop, required `*` on the server and then regularly calling

```
$ git annex sync --content
```

However, this is very slow (compared to --no-content, which takes seconds), it seems to iterate the whole repository for presence.

I'm not too familiar with git-annex's internals, but it seems finding a sparse set of present files is already implemented efficiently:

```
$ time git annex find --in=here
```

takes 5 seconds to complete on the laptop.
