DiskWarrior 4.0: Some Mac OS X 10.4.x disk directories cannot be rebuilt from Mac OS X 10.3.x

Note that some Mac OS X 10.4.x (Tiger) volumes -- specifically those with extended file attributes -- cannot have their drive directories rebuilt by copies of DiskWarrior running under Mac OS X 10.3.x (Panther). In other words -- if you are running DisWarrior from a partition or volume with Mac OS X 10.3.9 and attempting to rebuild a directory on a partition or volume with Mac OS X 10.4.x installed, an error may occur.

The reason is that Mac OS X 10.3.x cannot properly understand extended file attributes, used by Mac OS X 10.4.x to store file metadata and other information.

If you attempt to rebuild a drive directory with extended file attributes from a copy of DiskWarrior running under Mac OS X 10.3.x, you may receive the error message "The disk (name of disk) must be rebuilt while running Mac OS X 10.4 or later."

According to Rusty Little of Alsoft (developers of DiskWarrior), the intent of preventing Mac OS X 10.3.x-hosted copies of DiskWarrior from rebuilding Mac OS X 10.4.x volumes with extended file attributes is data integrity:

"While some of our competitors may take a 'looks good to me' attitude towards repairing damaged directories, we have a 'do no harm' policy with DiskWarrior. DiskWarrior has internal audits that include using the File System to verify the quality of the rebuilt directory. If there is a significant new addition to a File System, like EAs are with Mac OS X 10.4, and this kind of addition is rare, DiskWarrior needs to be running with a version of the Mac OS that can support our internal auditing systems."

Feedback? Late-breakers@macfixit.com.

Resources