Mac Inside & Out · Updates, Time Machine & Recovery · Lesson 2 of 5

Time Machine Backups

Back up a Mac to a drive, lock the backup, and bring back a lost file.

Setting up Time Machine

You learned earlier that a backup is a copy of your files kept somewhere else. On a Mac, the backup tool that comes built in is Time Machine. Once it's set up, it copies your files by itself, again and again.

You need an external drive, a small storage box that plugs into your Mac with a cable. Pick one with more space than your Mac has, so it can hold many backups.

To set it up:

1. Plug in the drive.
2. Open System Settings, click General, then Time Machine.
3. Click Add Backup Disk and choose your drive.
4. Turn on Encrypt Backup and make a backup password.
5. Click Set Up Disk.

Encrypting means scrambling the backup so only someone with the password can read it. This matters because a drive is easy to lose or steal, and it holds a copy of everything.

Write the backup password down and keep it somewhere safe. You need it to get your files back.

Your Mac may need to erase the drive before using it. So don't pick a drive that holds other files you need.

The first backup can take hours. After that, Time Machine only copies what changed, so later backups are quick. Keep the drive plugged in, or plug it in often.

On Windows, the closest built-in tools are Windows Backup and File History.

On the practice computer, add the backup disk, turn on encryption for the backup, and run a backup.

Going back in time for a file

Time Machine doesn't keep just one copy. It keeps a history, so you can go back to how a folder looked on an earlier day.

Here is how long each kind of backup is kept:

• Hourly backups for the past 24 hours.
• Daily backups for the past month.
• Weekly backups for the months before that.

In plain words: for today, you can go back hour by hour. For the past month, day by day. Further back, week by week.

When the drive gets full, Time Machine deletes the oldest backups to make room for new ones.

To get back a file you deleted or changed by mistake:

1. Open a Finder window for the folder where the file used to be, like Documents.
2. Click the Time Machine icon in the menu bar and choose Browse Time Machine Backups.
3. Use the timeline, the list of dates along the edge of the screen, to go back to a time when the file was there.
4. Select the file. Press the Space bar to peek at it with Quick Look and check it's the right one.
5. Click Restore.

The file goes back into its old folder.

One more tip. A drive that sits next to your Mac can be lost in the same fire or break in. For files you can't replace, keep a second copy somewhere else too, like iCloud Drive.