Explain HFS+ index key, node key?

[JGAN]

Couldn't find the correct section for this so sorry in advance,

When the HFS+ file system is corrupted, trying to repair it with tools like Disk Utility will return errors like

Code:

Index key doesn't match first node key
Invalid index key
(4, 56298)
** Rebuilding catalog B-tree.
BlockFindAll:  found 2646 blocks but needed 112798
CreateNewBTree returned -34
Disk full error
** The volume Data could not be repaired.


What exactly are the index key and node key though? I couldn't find anything detailing that in the structure of the HFS+ wikipedia page. Does it mean something like the starting LBA for the partition in the GPT is different from what the FS expects?

Not interested in data recovery, just an explanation of what this means.

[data-medics]

Sounds from that log that the catalog file is badly corrupted. Perhaps as the result of bad sectors in it.

I'd start by cloning the whole drive onto a good drive and see how that goes. Then I'd probably try running Disk Warrior or Data Rescue 4 against the clone drive. But, since you're not interested in data recovery I guess it doesn't matter.

The OS was trying to rebuild the block tree (B-Tree) but couldn't find anywhere close to the number of entries it expected to find (found 2646 blocks but needed 112798)

[JGAN]

So the B-tree is what tells the drive which blocks correspond to which files? What is the index key and node key though?

[Doomer]

So the B-tree is what tells the drive which blocks correspond to which files? What is the index key and node key though?

It's low level structures of HFS+ FS
If you need details, read this - https://developer.apple.com/legacy/libr ... n1150.html