Time Machine pauses when your Mac sleeps
Time Machine is supposed to back up automatically. And it does, as long as your Mac is awake. The moment macOS sleeps, the backup pauses. Wakes up, resumes. Sleeps again, pauses again.
For small incremental backups, not a big deal. For a first-time backup or one after weeks of changes? You're looking at hundreds of gigs that should take 3 hours but takes all day because the Mac keeps nodding off between your visits. Plug in drive, walk away, Mac sleeps after 10 minutes, backup stalls. Come back, wake it, walk away again. Repeat until you give up and sit there babysitting it.
The external disk condition
Shake It On has a condition called "Only Shake If external disk connected." Basically built for this. Plug in your backup drive, Shake It On detects it and starts keeping your Mac awake. Unplug the drive when you're done, shaking stops and your Mac goes back to sleeping normally.
No toggling anything. No remembering to turn it on before a backup or off after. The drive is the trigger. Plug in, stay awake. Unplug, sleep normally.
Works with any external drive, not just Time Machine volumes. Cloning with Carbon Copy Cloner, copying a big folder to an external SSD, same thing.
Recommended setup for backups
Here's what we'd configure:
- "Only Shake If external disk connected." The core piece. Shaking only happens when a drive is plugged in.
- "Paused When on battery." Big backups hammer the disk and drain battery fast. If you're backing up, you should be plugged in.
- "Allow display to sleep." Screen doesn't need to be on for a backup. Let it turn off while the system stays awake and Time Machine keeps copying.
- "Launch at login." So you never have to think about it. Plug in drive, backup runs, Mac stays awake. That's it.