[Cialug] Partition table gone

[Daniel A. Ramaley]

On Saturday February 21 2009, you wrote:
>On Feb 21, 2009, at 1:09 PM, Daniel A. Ramaley wrote:
>> If you think taking the first 512 bytes from another disk and
>> slapping it onto the front of my disk would fix the problem, that
>> would certainly be faster than my idea. I'd be willing to give it a
>> try if you can send me those magic 512 bytes.
>
>I don't particularly think it will work, but at 512 bytes it can't
>hurt to try. Attached, uncompressed.

THANK YOU!

That 512 bytes did it. The machine boots now. Linux fdisk now reports 
partitions, but they are wrong (i assume they are the partitions from 
the machine you pulled those 512 bytes from). I know rEFIt has an 
option to sync the various partition maps that exist on an Intel Mac; 
probably that will fix the inconsistency. But before messing with it, 
i'm going to make a backup.

>I think your copy data off, reparation, copy data back plan is a good  
>bet. Slow as all getup I'm sure, but it sounds like it will work so  
>long as nothing else is corrupted.

Imaging the disk took 5 hours, 49 minutes. I'm not sure why it was quite 
so long. I realize that it takes time to read a 320 GB notebook drive, 
but 6 hours seems a bit too slow. Copying over 100 Mbit ethernet 
shouldn't have imposed any real limitation. The destination drive on 
the destination machine is slow though; Western Digital has (had? -- i 
don't know if they still make it) a 1 TB drive that spins at 5400 RPM. 
Supposedly it varies between 5400 and 7200 based on usage, but in 
practice it is consistently slow. I bought it because i thought it 
would be quiet. It is indeed quiet, but dog slow, especially at 
writing. Since the TB drive is the one i use for backups, i don't 
actually care about speed so it works for my purposes. I'm glad though 
that i don't have to copy the MacBook image back. Still, now that i 
have the image and your magic 512 bytes that makes it bootable, i'll 
keep the image file around until i get the machine back exactly as i 
want it. At least now it is useable again and it will be easy to work 
with.

------------------------------------------------------------------------
Dan Ramaley                            Dial Center 118, Drake University
Network Programmer/Analyst             2407 Carpenter Ave
+1 515 271-4540                        Des Moines IA 50311 USA