Directory Damage, what can be used for Disk Repair and Virus Detection?

Question

Hi,
My eMac is acting up. Yesterday I started getting these messages that I needed to restart my computer (message was in a brown box window with an icon of a start up button in background).
I did the disk repair using Start up CD and it came back with "invalid key......." or something like that, and when I tried to repair it, it tried to repair the B-Tree's but then said it could not repair the problem.
I have Diskwarrior 3.03 Build 39, on a CD and on my FW Ext HD, which has a clone of my Mac HD.
Diskwarrior could not produce a graph of Mac HD because the directory was damaged. When I did a rebuild it hung on step 9 comparing directories, said there was 7 million + tests. ( I let it hang on step 9 for 15 hrs. to see if maybe it was just taking a long time due to corrupt directory). I finally clicked on Skip and got to the report page. I could do a preview, but the replace button is greyed out. When I was comparing the sizes of each folder, in both preview and original, I got a can not calculate error message on a few of them. The size of Mac HD in preview compared to the one in Original was different by 4 gbs. A week ago I repaired the Mac HD and did a Diskwarrior directory repair on all my HD's.
Before I do any reformatting of HD or other drastic measures, I was wondering what is safe to use for disk repair and virus detection. I know there is Norton System Works 3.0, Norton AntiVirus and TechTool, are these the only ones? Are these safe to use? Are there any other programs that can repair directory damage?
Thank you in advance,
Deb
eMac 2005 1.42GHz Combo Drive 256MB Tiger 10.4 75GB   Mac OS X (10.4)   Western Digital (WD) 160GB FW Ext & WD 320gb Media FW Ext, Creative Speakers

Answer 1

The long-standing rule of thimb has been that if Disk Warrior can't repair a mungled disk directory, then you're looking at reformatting or replacing the hard drive. Since this is a week-old hard drive, I'd suspect the replacement hard drive is itself bad. It might save you grief in the long run to contact the vendor who sold you the drive and inquire about their warrenty. You might want to first run the file system check utility fsck as described in Using Disk Utility and fsck
Directory repair and antivirus protection are different critters. Norton AV is mostly safe (if you don't mind it's track record of false positives) and is used by the IT department at the lab where I work. Norton SystemWorks, AKA Disk Doctor Kervorkian, is most assuredly NOT safe. For every poster reporting something nice about it, you'll find at least 2 dozen cursing it. It has a known track record of detecting problems no other utility finds and of "repairing" drives such that nothing can then read or repair the drive short of low-level reformatting (and occasionally even that fails).
Tech Tool Pro 4 has a good reputation, as does Drive Genius. Tiger OS X 10.4.2 and later include a version of Disk Utility that can for the first time also make effective B-tree and keys out of order and overlapped extent repairs. Still, my personal gut feeling is that if Disk Warrior is choking on the hard drive, you're looking at reformatring while zeros the drive (zeroing should detect and map out bad physical secotrs).
You can also refer to Disk First Aid: What to do when it finds an error and to Handling "overlapped extent allocation" errors reported by Disk Utility or fsck