Home / Mac / How-To
How-To

How to copy a failing drive to a backup using Mac Recovery

If your system appears to be failing, drop down to a lower-level tool.
Glenn Fleishman
By Glenn Fleishman
Senior Contributor SEP 3, 2021 2:00 am PDT
macOS Big Sur Disk Utility icon
Image: Apple

We don’t always know why a drive connected to a Mac starts to fail or the system becomes sluggish and nothing helps. If you’ve gone through routine troubleshooting and nothing fixes the problem—including reinstalling macOS as a last resort—you may want to try to recover the startup volume’s contents by booting using recoveryOS, a special partition in macOS designed for helping with what it says on the label: recovery!

First, restart your Mac into recoveryOS:

  • With an Intel Mac, choose  > Restart or power up your Mac. Hold down Command-R during startup until you see the progress bar beneath the Apple icon.
  • With an M1 Mac, power down your Mac normally if it’s active (via  > Shut Down). Then hold down the power button until “Loading startup options” appears, which can take about 10 seconds. Eventually, one or more drive icons will appear along with the Options icon. Click the Options icon and log in with an administrator account if prompted.

The macOS Recovery dialog appears and you can attempt to copy the startup volume:

  1. Attach an empty drive or one with an empty volume or one that can be erased that’s big enough to contain all the data in the startup volume.
  2. Choose Utilities > Disk Utility.
  3. Select the empty drive or volume. (If you don’t see the drive, choose View > Show All Devices.) Warning: The volume you select here will be erased and cannot be recovered.
  4. Choose Edit > Restore.
  5. From the “Restore to ‘empty volume name’?” dialog’s “Restore from” menu, select the startup volume you want to copy.
  6. Warning: When you perform the next step, the volume you selected will be irrecoverably erased. Click Restore and follow prompts.
  7. When complete, choose  > Shut Down.
  8. Disconnect the drive containing the copied volume and attach it to another Mac to recover files or use for migration.
Be very careful with this dialog: it erases the volume chosen by replacing its contents with the “Restore from” selection. People often think the reverse is the case.
Be very careful with this dialog: it erases the volume chosen by replacing its contents with the “Restore from” selection. People often think the reverse is the case.
Be very careful with this dialog: it erases the volume chosen by replacing its contents with the “Restore from” selection. People often think the reverse is the case.

This Mac 911 article is in response to a question submitted by Macworld reader Derek.

Ask Mac 911

We’ve compiled a list of the questions we get asked most frequently, along with answers and links to columns: read our super FAQ to see if your question is covered. If not, we’re always looking for new problems to solve! Email yours to mac911@macworld.com, including screen captures as appropriate and whether you want your full name used. Not every question will be answered, we don’t reply to email, and we cannot provide direct troubleshooting advice.

, Senior Contributor

Glenn Fleishman’s most recent books include Take Control of iOS and iPadOS Privacy and Security, Take Control of Calendar and Reminders, and Take Control of Securing Your Mac. In his spare time, he writes about printing and type history. He’s a senior contributor to Macworld, where he writes Mac 911.

Recent stories by Glenn Fleishman: