A Mac OS X volume can get corrupted for multitude of reasons. The first attempt of repairing a corrupted Mac OS X volume should always be to run 'Disk Utility'. But if this fails, you should try other
Mac Disk Recovery solutions such as, running fsck or reinstalling the operating system.
For more clarification, consider the worst scenario when you cannot boot your Mac OS X computer. Neither the normal boot nor the safe mode work and consequently, Mac is completely inaccessible. Thus, you try to fix the problem using 'Disk Utility' from Mac OS X install disc. But to your surprise, the tool doesn't work as expected. An error report is generated and you see errors similar to the ones specified below:
Error Message: Invalid file count (It should be x instead of x+1) AND
Error Message: Invalid volume directory count (It should be x instead of x-1)
Where, 'x' must be replaced by the expected count value.
Cause
The file system of Mac OS X volume is corrupted to an extent that 'Disk Utility' cannot fix it.
Solution
Since 'Disk Utility' has been unable to fix the file system corruption, you need to run force repair by running fsck command from command-line. To do so, follow the steps mentioned underneath:
Access the command-line by starting the computer in single-user mode
Once you reach the command-line, type the following command:
/sbin/fsck -fy
Press Return and the five phases of disk repair will start
Execute the above command repeatedly until the volume is reported OK
Type reboot and press Return
After the above steps, your Mac should boot normally. If it doesn't or fsck cannot repair the volume, the last resort is to erase the disk and install Mac OS X from scratch. However, to restore lost data, you need to use last backup.
At times, a Mac OS X user finds it unfeasible to get required information from data backup. To deal with such specific problems,
Mac file Recovery Software are available. These special utilities offer safe Mac File Recovery in any case of logical crash, while keeping the original data intact.
One of the best utilities is Stellar Phoenix Macintosh Data Recovery. This is a graphically rich Mac disk Recovery Software built for extensive disk scanning and comprehensive data recovery results. Supporting Mac OS X 10.6 Snow Leopard, 10.5 Leopard, 10.4 Tiger, and 10.3.9 Panther, this tool features advanced options.
