´Invalid node structure´ HFS Plus Error

HFS Plus is a file system with general volume format in Mac OS X. Out of all basic structures that these volumes use, Catalog File is the one that keeps records of all its files and directories. It is a B*-tree, which is divided into fixed-size nodes of 4 KB each. There are four basic types of nodes: Header node, Map nodes, Index nodes and Leaf nodes. Header node is the initial node to reference other nodes, Map nodes hold map records, Index nodes contain pointer records and Leaf nodes are responsible for holding data records. But sometimes, you encounter inconsistencies with these nodes, which can cause volume corruption. Such cases require reformatting of volume and data restoration from backup. However, in situations where backup is missing, incomplete or corrupt, you should opt for third party Mac Recovery software.

As a practical scenario, when you use Disk Utility to verify the integrity of HFS Plus volume, the following error message may get displayed:

"Invalid node structure"

The structure of nodes is common to all. It consists of three basic components: node descriptors, list of records and list of record offsets. Any damage to this structure makes the node corrupt and hence corresponding information can´t be accessed. To correct the issue, you need to follow these steps:

You can run fsck to repair tree corruption in single user mode

Third party disk repair applications can also be used for repair purpose

If the problem persists, you can perform Erase and Install to refresh the whole volume structure. As the process involves deletion of all stored information by reformatting, you should use your recent data backup to restore the data files. With data backup issues like no backup or backup not updated, you can use commercial Data Recovery Mac tools to recover your lost files.

Mac Recovery applications are available to solve problems of affected Mac drives and recover all lost and deleted information. You can use these applications for complete data recovery. Such tools are user-friendly applications with interactive interface, graphical documentation and self-descriptive screens. They incorporate advanced algorithms along with file signatures to recognize the data part of file system and actual files.

Stellar Phoenix Macintosh Data Recovery is the most powerful Mac Recovery tool. The application comes with bootable DVD for recovery of unbootable Macs. This Mac Data Recovery software supports HFS Plus, HFSX, HFS Wrapper, HFS and FAT file systems. It is compatible with Mac OS X 10.5.x (Leopard), 10.4.x (Tiger) and 10.3.9 (Panther).

http://www.macintosh-data-recovery.com/