Data Loss in Mac Due to Overlapped Extent Allocation

Under certain situations where fsck command line utility and Disk Utility might report overlapped extent errors in Mac OS X operating system. They may fail to detect and repair the file system issues. Due to the same, the Mac file system problem persists and your critical data remains inaccessible. To overcome such issues, Mac Data Recovery becomes mandatory with reliable tools and techniques.

When you attempt to find and repair file system errors using the Disk Utility and fsck command line utility in Mac OS X, you might come across the below error message:

"Overlapped extent allocation"

After this error message, the file system error checking and repair process fails.

Root of the issue

As stated in the error message, the process fails due to overlapped extent allocation in the Mac file system. The overlapped extent allocation refers to two files which occupy the same hard drive space. In such situations, at least one of the affected files would lose the data. If you are encountering this error, it means that the data loss has already happened to your drive.

Resolution

There are several solutions available to sort out this problem. Some of them are as follows:

Use Mac OS X 10.4.2 fsck or Disk Utility: The fsck tool and Disk Utility that come with Mac OS X 10.4.2 or later can recover your drive from such issues without affecting your data or volumes.

Erase the volume and reinstall Mac OS X: The effective way to fix this problem is to perform reinstallation of Mac OS X using Erase and Install method. But this solution is not safe as it deletes all the data from the volume.

If the first method fails, go for Erase and Install installation. By using this option, you will lose all your data from the selected Mac volume. In such cases, you need to opt for Mac Recovery solutions to recover the lost data.

You can easily recover your lost data in such situations by using powerful Mac Recovery Software. These software are specifically designed to scan the whole hard drive using efficient scanning algorithms and extract all your lost, missing or inaccessible data from hard drive or other storage media.

Stellar Phoenix Macintosh Data Recovery is the foremost solution to perform efficient Data Recovery Mac powered by boot DVD to recover data from even unbootable Macs. It supports HFS, HFS+, HFSX, HFS Wrapper and FAT file systems based Mac volumes. It is compatible with Mac OS X 10.5 Leopard, 10.4 Tiger and 10.3.9 Panther.