Washington Apple Pi

A Community of Apple iPad, iPhone and Mac Users

Report on Another Hard Disk Repair Utility

edited by Richard “Dick” Rucker

Washington Apple Pi Journal, reprint information

The following is a follow-up posting that appeared in this location on the Pi’s forums, http://tcs.wap.org/:Menu >> Computing >> Repair & Maintenance >> HD Repair Advice - Part 2

HD Repair Advice - Part 2 #1075
FROM: Richard Rucker
TO: All Tuesday, Jun 08, 2004
Last November, message #505 that started a thread entitled “HD repair advice,” began this way:

TidBITS#707 dated 24-Nov-03 has an informative review of the latest versions of five hard disk repair utilities for Mac OS X. The author is David Shayer who "was a senior engineer on Norton Utilities for Macintosh 3.0, 4.0, and 5.0. Before that he worked on Public Utilities, a disk repair program that won the MacUser Magazine Editor's Choice Award, and on Sedit, a low-level disk editor." I quote all that because the guy writes like he knows from experience.
In the article, he compared the capabilities of various disk repair programs to repair various hard disk problems that he managed, with the use of special tools, to inflict upon a real hard disk. Those programs were:
Norton Utilities 8.0
DiskWarrior 3.0
Drive 10 v1.1.4 from Micromat
Disk Guardian 2.2
Apple's Disk Utility

In yesterday's TidBITS#732 dated 07-Jun-04, David Shayer follows up with a review of TechTool 4 from Micromat and ranks it in with all the rest. It can be found here:
http://www.tidbits.com/tb-issues/TidBITS-732.html

A brief synopsis follows: The things he tested each candidate for were its ability to detect and correct:

• Bad Sectors; i.e., sectors with scrambled or unreadable data due to head crashes.
• Damage to the Allocation File which "tracks which blocks on the disk contain files, and which are empty."
• Damage to the Volume Header which holds data used to find "the allocation file, the catalog file, or any of your files."
• Damage to the Catalog File which "tracks all your files and folders."
• Damage to the Extents File which is used to supplement the catalog file when one of your files is so badly fragmented that the catalog file itself cannot keep track of all the fragments.
• Damage to Treads which are "used to look up folders and resolve aliases quickly."
• Overlapping Extents which occur "when the file system thinks two files occupy the same space on the disk.
• A Disk with a Slew of Problems: "I created a disk image... [where I] messed with the headers in some nodes, the records in various nodes, and the maps in some nodes."

In the TidBITS article, David explains how each of these utilities did in each test. But the bottom line per David is:

"I stick with my earlier recommendation for dealing with damaged disks. Try Apple's Disk Utility first -- since it is free and isn't likely to create any additional problems -- and if Disk Utility fails, hand the damage over to Disk Warrior, which has the best chance of fixing whatever ails your hard disk. And please, keep good backups!"