invalid node structure – rebuilding catalogue b-tree

[irishgrizzly]

My friends Macbook would only boot to a blue screen. So I booted from system disk and checked the HD. Got this error;
invalid node structure

And now it's;
rebuilding catalogue b-tree

It's been like this for over 10 minutes – is that normal? Is there anything else I should do?

Also does anyone know what might cause this? Is uit a sign of a failing HD or just a corrupt file (maybe during a system update)?

 

[davidlv]

invalid node structure
And now it's;rebuilding catalogue b-tree
Also does anyone know what might cause this? Is uit a sign of a failing HD or just a corrupt file (maybe during a system update)?

That is a corrupt/broken directory, not a file per se, and no it is not "normal" in the sense that it is not good, but it may be a "normal" error for a disk that has hardware problems.
1. If it is hardware, backup and punt (buy a new disk.
2. It may not be hardware that is the cause, in that case Disk Warrior can most likely fix the directory and you can recover most if not all of the files on the disk.
Disk Utility will give up if the corrution is bad.
In any case, I hope there is a recent backup of important files.