Filesystem verify or repair failed File in Mac OS X

Mac OS X file systems are considered comparatively more secure and safe from any corruption. But there still exist some situations that can corrupt these Mac OS X volumes. These volumes are comprised of metadata structures like, MDB (Master Directory Block), catalog file, etc. that might get corrupt and render the volume inaccessibile for the Mac OS X user. Most of such corruptions can be detected and repaired by built-in utility called 'Disk Utility'.

But if the problem remains unresolved, you should delete the corrupted volume provided a good backup of required data is available. But when no good backup exists, the solution is to run a Mac Data Recovery software and extract all the possible data. 'Disk Utility' can fail to repair the corrupted volume in many instances. To support the fact, let's consider a realistic situation when a Mac OS X user tries to mount a volume that has been named as 'Volume1'.

This volume contains most of the important files and folders, but to his/her surprise, when the volume is tried to be mounted, it cannot be mounted. Running 'Disk Utility' on this volume shows the below error messages:

Verifying volume “Volume1”

Checking Journaled HFS Plus volume.

Checking Extents Overflow file.

Error: Filesystem verify or repair failed.

This error by 'Disk Utility' indicates that the volume is corrupted- The file system of volume is corrupted. Such errors won't allow you to further access the files and folders stored in the affected volume. Issues, which cannot be fixed by 'Disk Utility' should be resolved by running fsck manually.

To do so, boot the computer in single-user mode and while the computer is booting up, press command (Apple) and S keys down. Next, you need to type fsck -fy command. If the issue still continues, you can delete the volume and restore data from backup. However, to extract data from corrupted volume itself, you need a Mac File Recovery solution. Mac Data Recovery software are easy-to-use products that can scan a corrupted Mac volume and recover all the lost data.