Mac OS X operating system can recognize file systems like, HFS, HFS+, FAT, and others. But for some reasons, if the file system of Mac disk gets corrupt or appears invalid, Mac cannot detect the associated disk. Such situations thereby create needs to Recover Mac data, especially when user fails to restore data from a backup.
To illustrate such problems, let's take the case of an external disk that you connect to your Mac OS X computer. You might view this disk in 'Disk Utility', but grayed out. On trying to mount the disk doesn't help either as on each attempt of doing so, you receive the below error message on screen:
“A disk attempting to mount as Unknown has failed verification or has failed to mount.”
Because the disk cannot be mounted, there is no way to access the disk and its data.
The above stated issue is most likely to occur because of the following reasons:
The disk you are trying to mount is formatted to an incorrect file system that Mac OS X is unable to recognize
The disk you are trying to mount is corrupted
Before troubleshooting the issue, make sure that the disk contains a valid file system that is recognizable to Mac OS X. If this is not the case, the prime solutions to file system corruption in Mac OS X are:
Run fsck to detect file system corruption and repair it
If running fsck doesn't make any difference, reformat the disk and restore the deleted data from you previous backup.
Mac OS X user often encounter backup-related concerns, in which they cannot restore from the backup. In such circumstances, the best possible solution is to use a Mac Data Recovery utility that can scan your hard disk and restore all the lost data in exact format. To Recover Mac data , all you require is to install one of the best applications, scan your hard disk, and restore the lost data to a safe location.
Stellar Phoenix Macintosh Data Recovery is a feature-rich utility to recover and restore lost/deleted data from Mac disks. Compatible with Mac OS X 10.6, 10.5, 10.4, and 10.3.9, this Mac Disk Recovery tool incorporates advanced, yet safe, scanning procedure and allows restoring your data to a secure location. The tool supports HFS, HFSX, HFS+, HFS Wrapper, and FAT file systems.
Some Tips to Solve 'A disk attempting to mount as