Automating Time Machine - Mount, Run TM, Unmount Overnight

I found really helpful information on how to do this here:

I’m only creating another thread to ask if anyone has tried something like this with shortcuts for MacOS yet? Before I use the scripts in the thread above I just thought I’d check to make sure there wasn’t a more “modern” way.

Goal - run TM overnight to the external USB drive connected to my CalDigit dock.

Why not run TM all the time?

  1. I want the ability to pull my laptop away from this setup without having to unmount any external drives;
  2. External spinning drive is loud. (I was solving this problem before, with my iMac Pro, via a very long USB cable that put the external drive around the corner. Now that I’m using a docked laptop setup until the next iMacs arrive, I need another solution.)


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You could probably do this by mounting and unmounting the drive, without fooling with TM, as TM will see when the drive is mounted and back up every hour until it is unmounted. By leaving TM enabled and running all the time, you can the advantage of its hourly snapshots even when the drive isn’t mounted.

Don’t know anything about this utility, but seems like it would do what you want. There’s also Keyboard Maestro which would be more flexible, but a little more fiddly.

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Yes, that’s exactly my plan for TM.

Thanks for the tip on Power Manager - I’ll check it out. Also makes me wonder if there’s anything in SetApp that can do this…

The tricky part is knowing when it is safe to unmount the drive. Has Time Machine finished yet? Did we wait too long and now it started another hourly backup?

This approach ( Automounting Time Machine ) seems to rely on triggering a backup after the drive is mounted (rather than waiting for Time Machine to notice) then using the completion of the backup as a trigger to unmount the drive.

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Maybe this isn’t the answer, because I do like having the constant TM backups happening when the laptop is docked.

I can move the backup drive off my desk with a long USB cable (that’s what I had with the iMac Pro). Then maybe I can program a Stream Deck button for “undock,” which unmounts all usb drives and plays a quick chime when complete? Not as good as “grab and go” but meets most of the need.