What to do when Disk Utility shows inconsistent errors with drives
Disk Utility’s format- and partition-checking routines can be run from various locations in OS X, such as within the main boot drive, from the recovery partition, or when using an alternative boot drive. You can also load your system into Safe Mode (holding Shift at startup), where similar routines will be run automatically.
These approaches to verifying the drive and partition tables should all show the same results, but this may not always be the case. In some cases, one routine such as using Disk Utility on the boot drive will show the drive as being perfectly fine, but when run from…
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