Almost every Mac user heavily relies on Time Machine to create and manage data backups. However, sometimes, even this reliable utility fails and leaves Mac users lurching in the dark. More often than not, the failure of the Time Machine utility is due to the failure of the drive used to store the backup.

A Time Machine backup drive provides safe home to years of accumulated data. Such data could include your work related documents, your personal files like photos and videos and other highly valuable data you possibly couldn’t imagine losing. Hence, it becomes extremely vital to understand the situations when a Time Machine drive and the Time Machine backup itself can fail, possible reasons for the failure and solutions for recovery.

Reasons for failure of a Time Machine backup

Time Machine drive failure

If on trying to access your Time Machine drive you hear a clicking sound, you should start bracing for shock. Your Time Machine drive might very well have failed. Since the Time Machine backup drive is just another hard drive (whether internal or external), the reasons for its failure are pretty much the same as other drives. These include:

• Sudden power outages while the drive was connected to your Mac
• Inadvertently dropping the drive in case it is an external one
• Unexpected mechanical failure
• Virus / Malware attack to the drive

Apart from understanding failure of a Time Machine drive, it is worthwhile also to note that a Time Machine backup could itself fail. That is, failure while taking or updating the backup.

Time Machine backup failure

You can spot that the Time Machine utility is having trouble creating or updating your backup if:

• The familiar ‘preparing’ progress bar which indicates that the utility is analyzing the backup drive continues to be in the ‘preparing’ mode after several hours, or in worst cases, even after overnight!
• The utility starts data transfer to the disk for backup but gets stuck midway
• It displays an error message saying, “The backup has failed”

If you face any of the above situations while trying to backup, well, you might very well have to start again. But why does it happen? Have a look here:

• If a large amount of data is being backed up, your Mac might go to sleep mode thus breaking the connection with the Time Capsule. Hence, if you anticipate that it will take a long time, a good idea would be to check from time to time if everything is progressing as expected
• Problems with Wi-fi connectivity
• Space running out while backing up due to unforeseen factors

If Time Machine backup fails, it has the potential to render your backup drive useless such that future attempts to backup also fail. Hence, it is important to understand how to set it right.

How to reset Time Machine 

The following steps will help you to reset the connection to your backup destination and replace the preferences file containing your settings for Time Machine.

Note: This procedure will not delete anything in your backups, or cause Time Machine to start a new set of backups.

1. Turn Time Machine “OFF” from the Time Machine ‘Preferences’ window after making sure that no backup is running. Turning it off doesn’t cancel a running backup so you’ll have to do this manually.
2. If you’re using an external drive for the backup, connect it temporarily.
3. Go to Preferences -> Options and take a print screen of the settings. Then click on Cancel and quit the Preferences.
4. If you’re using an external hard drive, disconnect it and power it off. Then after a few seconds, reconnect it.
5. Open Finder and from the Menu bar select Go -> Go to Folder. Copy /Library/Preferences to the prompt and click ‘Go’. Scroll down until you find the file com.apple.TimeMachine.plist and delete it.
6. Open the Preferences window again. If your backup drive is still selected, the contents of the old file are still there. Restart your Mac, and delete the file again. Make sure to re-enter any exclusions you took a print screen of in step 3 before deleting.

Once you’ve followed these steps, a 120-second countdown to a backup should appear. If you close the preferences window, it should begin immediately.

Final Words

So follow the above steps to fully reset your Time Machine backup in case it fails. However, if the Time Machine backup drive itself has failed, first find out what kind of failure it is – mechanical or logical. In case of a mechanical failure resulting from physical damage, you’ll most likely have to take the drive to a recovery center. However, if it is a logical failure, you can repair it yourself using good quality Mac data recovery software like Stellar Phoenix Mac Data Recovery. So stay aware, stay safe!