What do you mean by "reformatted"? I'm not an expert on how disk drives work, 
but here's my experience, which has worked for me.

The same thing happened to me last week on a 4 year old MacBook Pro original 
internal drive, with the same error message. Disk Utility refused to repair the 
disk, as per the error message. A test using some other utility (I forget now, 
maybe TechTool Pro) told me "bad blocks". Using Disk Utility, I erased the disk 
**using the write-zeroes-once option** because that maps out bad blocks so they 
won't be used again. 

Then I restored from my most recent Time Machine backup. The MacBook Pro 
wouldn't boot at all after that (no error messages), but examining it from an 
external startup drive showed a huge number of files with obscure names (more 
than 11,000) in the "DamagedFiles" folder (created, I believe, by Time 
Machine). I assumed they were corrupted blocks somewhere in the system that had 
gotten backed up to Time Machine over a period of time. So I reinstalled 
Mountain Lion from the original Mountain Lion installer and applied the 10.8.3 
combo updater. This left all my other files from the previous restore intact, 
including applications and data. The MacBook Pro is now back to normal and 
working fine for the past week or ten days.

This exact same thing had happened on the same drive about a year ago, and the 
same fix lasted for the past year. 

Of course there may still be corrupted blocks in my applications and data that 
had been backed up to Time Machine and then restored, but so far I haven't run 
into any. I use a very large number of applications and files on this MacBook 
Pro about 14 hours every day in my law practice and in my programming career, 
so I'm fairly confident that I have a usable system now.

If you're merely erasing the disk without writing zeroes, your bad blocks are 
still mapped in and still being used. And restoring from backup may be 
restoring corrupt blocks, too. I assume either of these issues could lead to 
the same failure message, but certainly reusing bad blocks could. I don't know 
whether there is such a thing as "flaky" blocks, but maybe you would get normal 
behavior for a few days following an erase and restore before the next failure 
of a critically located flaky block.

Bill

On Apr 23, 2013, at 9:52 PM, Kevin Callahan <[email protected]> wrote:

> In fact, it happened 3 days ago. I reformatted, created a brand new backup.  
> Now tonight, once again.
> 
> Clues as to what causes this?

-- 

Bill Cheeseman - [email protected]

_______________________________________________
MacOSX-talk mailing list
[email protected]
http://www.omnigroup.com/mailman/listinfo/macosx-talk

Reply via email to