When bad things happen to good Mac's [OT]

[Mark Guertin]

Just wanted to chime in on a few things from this thread..

These 3 utils are all very different beasts (mostly anyway).

Diskwarrior doesn't repair your files, it rebuilds the file catalogs  
by analyzing the files in their current states.  It's the only tool  
out there that I know of that takes this approach, and in most cases  
it will get you back to working order most promptly with the least  
chances at major damage (it doesn't try to fix the damaged files --  
which more often than not will leave you dead in the water if they  
were important ones that were semi functional hehe).  It also allows  
you to preview the newly built files before committing.  I'd be  
surprised if there wasn't also a way to roll it back before you make  
any disk commits, but sadly that doesn't seem to be part of the app  
bundle :/

Daniel, if you blew away the OS9 patch partitions with Drive Genius  
there's a good reason why you can't boot OS9 anymore.  pdisk can put  
the partitions back in place but the drivers required are not  
installed by pdisk because the boot driver is proprietary to apple  
and is required for OS9 to be able to boot the media (and the main  
reason why oldworld can't boot linux from a cdrom as this also  
requires apple's proprietary code).  The only free (as in speech)  
tool I know of that can do this is mkisofs which won't help you much  
in this situation as it can only be used to make bootable cd media  
which uses a slightly different approach to the drives .. and not  
sure that mkisofs can even do this anymore :(

You might have some success booting that drive from OS9 again if you  
can get into any OS9 that is running and mount the drive, and then  
using apple's drive setup program tell it to "update" the drivers on  
that disk (which should be non destructive in theory, YMMV)... in  
some cases it might also need a tiny bit more unpartitioned space on  
the drive to put in extra patch partitions (which is also why apple  
always left a bit of unpartitioned space on factory drive setups  pre  
OSX to allow for future driver updates/addons).

Techtool uses it's own hfs/hfs+ repair tools to do the dirty work  
(and not fsck, which I bet drive genius does -- probably why neither  
fsck or drive genius could fix the damage).  Again the now gone  
Norton Disk Doctor had yet another set of repair tools.  These apps  
take a different approach than Diskwarrior, in fact the opposite.   
They look at the catalogs and then try to match up all the files in  
the filesystem to them, repairing things as found and needed, and  
they do a muc more in depth scan of the files themselves and rarely  
touch the catalogs.  have you ever seen the screen in Disk Doctor  
that dumped you into the "filesaver" mode?  That basically meant that  
the catalogs were corrupted beyond repair and it did the  diskwarrior  
type thing to try and find any files that were intact...

Drive Genius is different again in that it's a front end for a bunch  
of command line type tools (check inside the .app bundle) that allow  
you to do things that OSX and these other tools don't necessarily let  
you do, like repartition without destroying your data... or break  
things if you tell it to ;)

I fix macs pretty much for a living and I have all these tools in my  
toolkit (plus some others, like applejack) and they have all pulled  
the bacon from the fire so to speak at different times over many  
different OS versions ;)

Anyway, just wanted to toss some more info into the thread.

Mark

On 20-Jul-05, at 11:41 PM, Derick Centeno wrote:

> Thanks Daniel for providing that experience and detailed report.  I  
> thought Drive Genius would be an alternative to DiskWarrior, but  
> not after reading what you said.
>
> So the competition is between DIskWarrior or Micromat, and that's  
> it.  It's going to be interesting to see what occurs in a few months.
>
> Best wishes....
>
> On Jul 20, 2005, at 10:24 PM, Daniel Gimpelevich wrote:
>
>
>> I tried Drive Genius's partition resizing function in conjunction  
>> with its
>> partition map reset function. As a side effect, it wiped out the OS9
>> driver partitions, and even though I managed to restore them (with  
>> pdisk)
>> to a state where OS9 can see the disk again, I still have not been  
>> able to
>> boot that machine into OS9 since then. To top things off, the  
>> resizing of
>> the partition left the filesystem in exactly the predicament Dr.  
>> Sacco
>> described. Both fsck and Drive Genius would say that repair is  
>> needed, and
>> then refuse to do it. My next stop was DiskWarrior, which took  
>> care of
>> that problem. I still had TechTool Pro ready as a last resort.
>>
>
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