Resolve issue: Time machine failed to backup Mac


Apple Inc has developed a utility, known as Time Machine, to backup all the data of your computer. The software creates incremental backups of the files that can be restored at a later date. This is the best backup utility for Mac OS X users. Sometime, Time machine failed to backup Mac hard drives. You may receive several message when the utility fails to backup such as:


“Unable to complete backup. An error occurred while copying files to the backup volume.”

“The backup volume is read only.”

“The disk (Volume name) was not repairable by this computer. It is being made available to you with limited functionality. You must back up your data and reformat the disk as soon as possible.”




This is the critical situation where the time machine failed to backup. The reason behind the failure of back up can easily be observed from the above messages. In order to troubleshoot the time machine backup problem, you will have to understand the messages you received and take appropriate action against the problems.


If time machine backup failing Mac OSX again and again. You receive message like “Unable to complete backup. An error occurred while copying files to the backup volume.” then you will need to restart your computer that might automatically fix the problem.


If Time Machine is using external hard drive to backup and you receive backup failure message message like “The backup volume is read only.” or “The disk (Volume name) was not repairable by this computer. It is being made available to you with limited functionality. You must back up your data and reformat the disk as soon as possible.” then follow the following steps to resolve the time machine backup problem issue:

  1. 1. In the Apple menu select System Preferences
  2. From View menu, select Time Machine
  3. Disable the Time Machine backups by moving slider bar to 'Off'
  4. Open Disk Utility located in /Applications/Utilities
  5. Mount your external hard drive
  6. In Disk Utility, locate the external hard drive where you want to backup.
  7. Select the external backup drive
  8. Click Repair

In case the external disk is unable to mount then you will have to format the drive. If you have stored your important data within the drive then you will have to take help of Mac data recovery software to recover the lost data after format.


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