DadCloner

DadCloner is a tiny macOS menu bar app for automatic external drive backups. It uses rsync, remembers the exact source and backup drive UUIDs, and never deletes files from the backup. When something disappears from the source drive, DadCloner moves the backed-up copy into an archive folder instead (folders left empty after their contents are archived are cleaned up).

Built for the kind of backup job where the safest restore path is "plug in the drive and browse normal files."

My dad's 75 and has decades of recording sessions and jingles on external drives. He needed backups that would actually happen without him thinking about it, and couldn't risk anything getting deleted. Time Machine was a non-starter. Mac OS 9 was his jam, his dock is longer than War and Peace. So, let's keep it dead simple:

Download

Download the latest release from the GitHub Releases page.

DadCloner 1.0 updates itself: when a new version ships, the app offers the update automatically.

How it works

Pick a source drive. Pick a backup drive. Set a schedule. Done.

The app syncs changes automatically using the bundled rsync binary. If a file gets removed from the source, the backed-up copy moves to a DadCloner_Archive folder on the backup instead of disappearing forever.

Everything lives in a DadCloner Backup folder on your destination drive:

• Mirrored files from source
• DadCloner_Archive/ subfolder for anything that got removed

Features

• Menu bar app for scheduled macOS backups
• Non-destructive backup behavior: no --delete
• Exact drive matching by volume UUID
• Free-space preflight before a backup starts
• Catch-up sync after missed schedules, including right after the Mac wakes from sleep
• Settings for changing the schedule, pausing backups, or re-picking drives after setup
• Failure reasons shown right in the menu bar popover
• Built-in updates via Sparkle
• Sync log capped at 512 KB so it never grows unbounded
• Visible status for mounted drives, running syncs, and failures
• Notarized Developer ID builds
• Bundled rsync 3.2.7; no Homebrew required

What it doesn't do

• Touch your source drive (read only, always)
• Use --delete or any other destructive rsync flags
• Format or partition anything
• Require you to think about it after setup

Current limitations

• Apple Silicon only, because the bundled rsync helper is arm64.
• Not a versioned backup system. It keeps the current mirrored copy plus archived files that disappeared from the source.
• No cloud sync, encryption, drive formatting, or network backup support.

Building

Xcode 15+. The app bundles rsync 3.2.7 so it works without Homebrew.

The bundled rsync binary is currently Apple Silicon only. For Intel Macs, replace DadCloner/Resources/rsync with an x86_64 or universal rsync binary before building.

git clone [repo]
open DadCloner.xcodeproj

In Xcode:

1. Select the DadCloner target in the project navigator
2. Go to Signing & Capabilities
3. Set your Team to your Apple Developer account (or Personal Team for local builds)
4. Build and run

Core logic (rsync output parsing, schedule math, orphan scanning, log rotation) lives in the DadClonerCore Swift package. Run its tests with:

swift test --package-path DadClonerCore

Releasing

Use a Developer ID Application certificate for public builds. Sign the bundled rsync binary before re-signing and notarizing the app bundle.

Basic release checklist:

xcodebuild -project DadCloner.xcodeproj -scheme DadCloner -configuration Release clean build
APP="path/to/DadCloner.app"
IDENTITY="Developer ID Application: Your Name (TEAMID)"
codesign --force --options runtime --timestamp --sign "$IDENTITY" "$APP/Contents/Resources/rsync"
codesign --force --options runtime --timestamp --entitlements DadCloner/DadCloner.entitlements --sign "$IDENTITY" "$APP"
codesign --verify --deep --strict --verbose=2 "$APP"
ditto -c -k --keepParent "$APP" DadCloner-1.0.zip
xcrun notarytool submit DadCloner-1.0.zip --keychain-profile "notarytool-profile" --wait
xcrun stapler staple "$APP"
spctl --assess --type execute --verbose=4 "$APP"

Do not ship a "Sign to Run Locally" build. The release artifact should show a Developer ID signature and a successful notarization result.

After notarizing, sign the zip for Sparkle and add an <item> to appcast.xml:

sign_update DadCloner-1.0.zip   # from Sparkle's bin/, prints edSignature + length

Commit the updated appcast.xml to main — the app reads it from GitHub raw.

License

MIT. Use it for your parents, rebuild it, whatever.