Guide · Mac

Back up your photos and video every time you plug in the drive

You finish a shoot or an edit, plug in the backup drive, and drag folders across, hoping you got all of them and didn't overwrite anything. Here's how to make plugging the drive in the whole job.

What you're setting up

One rule: whenever this drive is plugged in, copy anything new or changed in my work folder onto it, and never remove anything from it. You set it up once. After that you plug the drive in, wait for it to finish, and eject.

You'll need your work in a folder (or a few) on the Mac, and an external drive with room for all of it. This works with any folder of files: camera cards you've imported, Lightroom Classic or Capture One folders, video projects and their media, exports.

Setting it up

This uses Stow™. The steps take about two minutes.

1. Plug in the backup drive and open Stow. Click New sync.
2. Under From, choose your work folder. Under To, choose (or make) a folder on the drive.
3. Choose Only ever add. New and changed files get copied, and nothing on the drive is ever removed, so culling rejects or clearing space on your Mac never touches the backup.
4. Under When should it run?, choose Whenever the drive is plugged in. It runs once each time you connect the drive, not again while it stays connected.
5. Read the sentence at the bottom. It says what will happen, in full, before you save. Then click Save and preview results.
6. The first time, Stow shows every file it's about to copy, so you can check you picked the right folders. Click to run it.
7. When Stow asks, let it start when you log in. It can only notice the drive while it's running.

The first run copies everything, so give it time. Every run after that copies only what's new or changed since the last one.

Each time you're done

1. Quit your editing app if its catalog, library or project file is in the folder. Those are databases that change while the app is open. The photos and footage themselves are fine to copy at any time.
2. Plug in the drive. The run starts on its own.
3. Click Stow in the menu bar. While it's working it says Running with a percentage. When it says Everything up to date, eject the drive.

If a run can't finish, because the drive is full or a folder couldn't be read, Stow tells you and says why, rather than leaving a backup that's quietly missing things. If you unplug the drive partway through, that run is marked as not finished, nothing is written to your Mac in its place, and the next plug-in picks up what's left.

Things worth knowing

• Edited files replace their old copy, but the old copy is kept. When a changed file is copied over its older version on the drive, the older one goes into a safety net on the drive for 30 days. You can put it back from inside Stow.
• A changed file is copied whole. Re-export a 20 GB video and all 20 GB is copied again. Stow doesn't copy only the changed parts of a file.
• Two drives are better than one. A backup on a drive that lives next to your computer doesn't survive a fire or a theft. Set up a second sync to a second drive the same way, and keep that one somewhere else.
• Check that it opens. Every so often, open a few photos and clips straight from the drive. A backup you've never opened is a guess.