Disk Utility is good at resolving minor errors that occur on Macintosh HD or other partitions. It is sad to admit if the Mac encounters ‘Invalid Node Structure' error then DU won't be of any help. This error itself is serious and will surely cause the hard drive to behave abruptly if not repaired timely. In short the corruption of Mac hard drive directory structure is called as Invalid Node Error.
You turn on your Mac only to find that it gets stuck on the Apple logo and won't go any further. When you restart the system, you have problems with your Dashboard and a few applications start behaving oddly. If you find yourself bumped into a similar situation, you would certainly head for a repair using Disk Utility. It is no surprise that Disk Utility is the application of choice for most Mac users, as it can remedy disk corruption issues quite easily. However, it may not fix all errors in your directory structure. It can only make repairs that it has been programmed for.
It is quite often the case that Mac users come across the ‘invalid node structure' error. This error cannot be repaired by Disk Utility, and thus many are still oblivious to the fact that it is possible to get rid of this problem. It would be a pain in the neck to back up everything to an external drive, and then reinstall OS X and all applications on your Mac to get it working as before. The fact of the matter is you can do it all yourself using some tweaks and following an easy-to-use procedure. All you need to do is clone your internal hard drive to an external drive, make sure you can boot from it and it works fine, and then clone everything back to the internal drive.
How to Fix “Invalid Node Structure” Error on Mac
You can use Disk Utility or any of the free tools out there in the market for the cloning job. The following procedure will guide you how to get your system back up and running after facing the ‘invalid node structure' error:
Step #1. Download any of the free cloning software available on the web to perform reliable and risk-free cloning.
Step #2. Take a FireWire drive and connect it to your Mac. Use Disk Utility to create two partitions on this disk, and then zero out all data stored on it. You can create a bigger partition ‘A' of size greater than that of your internal hard drive and a smaller partition ‘B' (approx. 8 GB to accommodate a basic OS X package.)
Step #3. Perform basic OS X installation on partition ‘B' and make sure you do not install any additional programs like iPhoto, iTunes, etc. You should try booting from your FireWire drive and make sure it works fine. Boot your Mac using the internal drive and run ‘Verify Disk' function of Disk Utility to check the FireWire drive for errors. If it works as expected, proceed to the next step.
Step #4. Boot from the internal hard drive and use the free cloning program you downloaded to clone partition ‘B' to partition ‘A'. You can boot from this partition and verify that it works fine. This is to be on a safe side and ensure that you have a working copy of OS X.
Step #5. Next, boot your Mac using partition ‘A' and import every piece of useful information and programs from the internal Mac hard drive to this partition. This can be easily accomplished via Migration Assistant. The FireWire drive will show two users as administrators. You can use the user id that was on the internal drive. Migration Assistant may report some errors and state that some programs need to be reinstalled. You can skip them for now and perform these actions later. Once the Migration Assistant has finished importing, you will find all the migrated programs in a folder on your desktop. It is better off moving all these programs to the Applications folder created by the OS X installation because a few applications may throw errors when started from a location other than the Applications folder.
Step #6. Before proceeding further, you need to make sure all the programs you have migrated using Migration Assistant are working fine. To do so, you will have to invest some time running these programs one by one and checking if no errors are encountered. You might require installing updates to some applications. At the same time, you might receive errors stating that you cannot install updates on external disk. To do away with this, you simply run updates to OS X during the night hours.
Step #7. Next, you should ensure that you have everything backed up on the FireWire drive. Now, boot from partition ‘A' and wipe your internal hard drive using Disk Utility. This would erase all data on your internal hard drive beyond the scope of recovery. For convenience, partition your internal hard drive as per your space requirements.
Step #8. Restart your Mac using partition ‘B' and use the cloning tool to clone partition ‘A' onto a bigger partition on your internal hard drive.
Now, you have prepared your internal hard drive with all the data and programs installed earlier. You can boot from this drive and check if problems persists. In case you encounter errors again, use commercial tools to perform data recovery on your Mac.