The disk is unreadable” error on external Mac OS X drive

Hierarchical file system (HFS) is an advanced file system used on hard drives and removable storage media. It is a reliable file system providing secure data storage in mac systems. Still, situations like accidental power failure, virus infection, hardware failure, improper system shutdown and such other can damage the HFS file system leading to data loss.

An external or portable hard drive occupies an important utility for computer users today. Using it data can be stored or backed up in drives other than the internal hard drive. It can also be used if you want to transfer data from one system to another. There can be situations when access to the data stored in external hard drive is not possible and this arises data loss situations. For restoring which you may have to use data recovery mac which locates data by scanning the drive and extracts it for accessing.

In a particular situation, error as “the disk is unreadable: Do you want to initialize it now” may be acknowledged. Here the first attempt would be fixing the problem with disk utility program, but it may end up with error as- file system verify or repair failed

• After starting the process as Verify and repair volume “disk1s3”
• Checking journaled HFS plus volume
• Invalid node structure
• Invalid B-tree node size
• Invalid node structure
• Volume check failed

Such a problem occurs due corruption in node or file system structure and the system data structure, user profiles and library files of Mac OS X drive becomes inaccessible. The only option then left is initializing the drive as suggested in “disk is unreadable” error message. In Mac OS X, drive initialization is done in 3 steps as-

• Disk formatting
• Disk verification
• Disk zeroing

Once it is done, the drive is now error free, without any file, directories or data which simply means all your data is lost. But, just with the use of data recovery mac on the affected drive, complete restore of data is possible. It is because of its powerful in depth scanning thereby locating the files as they are still present but inaccessible due missing file system directory that makes the file available for use. After searching is completed, the required files from the search results can be selected for restore. Easy use, intuitive interface and support to HFS, HFS+, HFSX, HFS wrapper file systems of Mac OS X including snow leopard are its other feature. Thus, an efficient means of solving Mac OS X errors and retrieving data.