Disk First Aid: What to do when it finds an error
Learn what to do when Disk First Aid reports an issue with the disk. This document applies to Mac OS 9 and earlier. It does not apply to Disk Utility or Mac OS X.
After attempting to repair a disk, Disk First Aid reports one or more of the error messages listed below, followed by, "Problems were found but Disk First Aid cannot repair them".
- 1. Back up important data from the disk if possible.
2. Start up from CD and use the Repair option of Disk First Aid to try to repair the volume. If Disk First Aid continues to report an issue with the volume, try running Disk First Aid a second or third time to ensure that the disk cannot be repaired by Disk First Aid.
3. If Disk First Aid is not able to repair the disk, consider using a third-party disk utility to try to repair the disk.
4. If Disk First Aid is not able to repair the disk and a third-party utility is either unavailable or unable to repair the disk, back up important data from the disk if possible, and reformat the disk using Drive Setup.
Explanation of selected "error" messages
Message: Missing Thread Record
Disk First Aid reports the following:
- Checking catalog file.
- Problem: Missing thread record, 3499, 160
- Rechecking catalog file.
- Test done. Problems were found, but Disk First Aid cannot repair them.
When Disk First Aid reports that the thread for a file is missing and it cannot repair it, this means that it is unable to reconcile the entry for the file in the directory (catalog B-tree) with the location of the file on the volume. This indication can be triggered by the following:
- The file in question may have become damaged and cannot be repaired.
- The catalog B-tree may have become damaged and cannot be repaired.
- An earlier version of Disk First Aid (which cannot repair volumes currently in use as the startup disk) is being used to try to repair the startup volume. Try booting from another volume such as a System Install CD, and run Disk First Aid from the CD.
Message: Disk First Aid Internal Error
Disk First Aid reports an "internal error" during verification or repair of a disk.
If Disk First Aid detects a fault with the volume structure that does not conform to what it knows a reliable volume should look like, and it cannot identify it among its list of known issues, Disk First Aid reports the fault as an internal error.
Message: One Item In Trash, Cannot Be Emptied
Sometimes the Trash has one item in it and cannot be emptied.
Folders that cannot be thrown away may suggest a directory issue or a Finder flag issue.
Message: "Disk With Bad Name" Error
Disk First Aid reports a "Disk with Bad Name" error. The disk seems fine in every other way.
This message may actually indicate other issues with the disk such as bad data in the boot blocks of the hard drive, or possibly a bad pointer.
If an earlier version of Disk First Aid (which cannot repair volumes currently in use as the startup disk) is being used to try to repair the startup volume, try booting from another volume such as a System Install CD, and run Disk First Aid from the CD.
Message: Keys Out of Order
Disk First Aid reports "Keys Out of Order".
B-tree records or referenced records have become damaged.
Message: Bad Leaf Node/Index Node
Disk First Aid reports "Bad Leaf Node/Index Node".
A node has been changed and no longer correctly refers to other nodes or records.
Message: B-trees Damaged
Disk First Aid reports "B-trees Damaged".
The B-tree (part of the disk directory) has become damaged and cannot be repaired by Disk First Aid.
Message: Volume Bitmap Incorrect
Disk First Aid reports "Volume Bitmap Incorrect".
The volume bitmap is not accurately reflecting the use of allocation blocks on the drive. Disk First Aid will attempt to repair this, and the extents file, by comparing the two with each other, then comparing against the actual allocation blocks on the drive.
Message: Bundle Bits Need to be Reset
Disk First Aid reports "Bundle Bits Need to be Reset".
The Bundle Bit flag needs to be reset for one or more files. (Other Finder flags may also need resetting).
For related information on this topic, please see the following articles:
Article 7565: "Disk First Aid: Purpose"
Article 19516: "Mac OS: Technical Overview of Disk Volume Structures"
Article 8647: "Macintosh: File System Specifications and Terms"
Article 30344: "Mac OS: About Mac OS Extended Format"
Article 24601: "Mac OS Extended Format: Volume and File Limits"