This is the most recommended method to repair the error. Formatting the hard drive or partition scheme will recreate a new HFS file structure on the hard drive, which will be free from cryptic errors. The one and only requirement are that Disk Utility must reside on the drive. Disk Utility can be run from the external drive. The reason for this error is the modification of the boot drive, or it is being used by some other process or application. The error occurs in such situations like formatting Mac as well as partitioning and verification and repairing of Mac disk. They are unable to erase or partition the drive. The user often experiences a problem, while handling some of the Macs, when they are not allowed to repair permissions or directory in Disk Utility. Take a free trial of Stellar Data Recovery for Mac to see how it can actually help you in various data loss situations. So, we recommend you to have a Mac data recovery software by your side to get back the lost data. Fixing With Recovery Partition Due to unmounting error, there could be chances of data loss.
