How to automatically eject external drive after Time Machine runs

Question

I have a MacBook Pro which I regularly dock to an external monitor.

I have my mouse, keyboard, and iPhone dock, and an external hard drive connected via a USB hub so that I only have to make one USB connection when docking.

The external hard drive is used for Time Machine backups. Every time I undock, I simply unplug the single USB cable. Unfortunately this causes a warning message that says that I should remember to eject the external hard drive before unplugging it.

What I would like to know is if there is a way that I could have it automatically eject the external hard drive each time after Time Machine runs.

I usually undock and redock at least once a day so the next time it is docked, the drive will be re-mounted and then Time Machine could run while the system is docked.

Solution 1

I found a free and useful downlaod that does this:

Time Machine Scheduler

It mounts and unmounts the drive automatically on schedule (and when you boot up, if you ask it to). Also allows a custom schedule other than every hour. It installs a new pref panel to control this. Only downside is that the old TM pref panel does not display everything exactly right anymore -- timestamps are off by a few minutes, it says Time machine is Off even when backups are happening -- but it completely solves the pesky improper ejection issue.

Solution 2

You could do a backup using the terminal and eject using the terminal. Then put the commands into a script.

Comments

[Admin]

Seems like this defeats the purpose of Time Machine since it is meant to backup at regular intervals so long as the drive is mounted.

[Admin]

Yes, but it usually gets docked once a day so it is still able to backup periodically. I'm not sure what the default interval is but it seems to back up once a day or so.

[Admin]

Once an hour. It might remove hourly backups from the backup disk to preserve disk space, though.

[Dannid]

I would upvote this answer if you repeated the details in your answer. It's fine to link to other sources, but other sources have a habit of going away...