Upgrading to Leopard Creates 'Invalid Sibling Link'

In Apple Mac OS X the Disk Utility which allows to perform disk tasks, such as formatting, repairing, partitioning, changing partition scheme and more. On occasion, the tool might fail to repair the disk, generally when you are using it from within Mac OS X system. It requires you to execute administrative tools without starting any system service or mounting any disk partition. If this also fails, you need to erase the disk and restore from backup.

In some cases when the backup fails or does not work, you should use Mac File Recovery software that could safely restore all lost files and folders while the process. Consider that you use a Tiger based system dual-booted with Windows. You upgrade your Mac partition to Leopard. After this, when you try to access Mac partition from Windows, you fail to do so. Also, attempting to repair the partition using Disk Utility doesn't help as it finds the partition unable to mount and giving the below error:

“Invalid Sibling Link”

You cannot access the Mac partition and its data. Partition table or file system of the disk is corrupted.
Since Disk Utility fails to repair the disk, you need to try these steps to repair it:

Boot the computer using Mac OS X CD to load the installer
Select 'Utilities' from the menu option and run the Terminal
Execute fsck_hfs -r /dev/ partition_name, while making sure that the target partition is not mounted
Try to duplicate the behavior

If you still cannot access the partition and system is unstable, you need to erase and repartition the disk:

Boot the computer using Mac OS X install CD
Select Disk Utility from the 'Utilities'
Erase and repartition the disk
Reinstall Mac OS X
Restore data from recent backup available

If this helps but you find issues restoring from backup, use an effective Mac Recovery product. Designed with suitable and safe algorithms to recover data, these Mac File Recovery applications serve as powerful data recovery applications to extract lost data from a logically crashed Mac drive.

This software is safe Mac Drive Recovery software that is compatible with Mac OS X 10.6 Snow Leopard, 10.5 Leopard, 10.4 Tiger and 10.3.9 Panther. The tool incorporates powerful data searching algorithms and provides advanced features. It supports HFS, HFSX, HFS Wrapper, HFS+ and FAT file systems.