[Cialug] Partition table gone

[Daniel A. Ramaley]

I have an "interesting" problem. A 2-year old Macbook with a 320 GB 
internal drive has had the first 512 bytes of said drive zeroed. Now it 
won't boot from the hard disk. Booting from an OS X CD, the disk 
utility shows the entire drive as blank and all ready to be partitioned 
and formatted. Which would be great if i wanted to reinstall everything 
from scratch. But i'd rather recover the partitions than lose all the 
(non-backed up) data and have to start over.

Booting from a Ubuntu 8.10 DVD and running GParted shows a different 
(and more hopeful) story, however. It shows all 3 partitions that are 
supposed to be there:
sda1 - fat32, 200 MiB  <-- Intel Macs need this
sda2 - hfs+, 200 GiB   <-- OS X installation
sda3 - ext3, 97.90 GiB <-- Ubuntu install

I've never used GParted before, so i'm not sure what its correct 
behavior is. However, if i double click on each partition, i can see 
the numbers of the start and end sectors. But, there's also a "Warning" 
box that displays things like this:
--------------------BEGIN--------------------
e2label: No such file or directory while trying to open /dev/sda3
Couldn't find valid filesystem superblock.

Couldn't find valid filesystem superblock.

dumpe2fs 1.41.3 (12-Oct-2008)
dumpe2fs: No such file or
directory while trying to open /dev/
sda3

Unable to read the contents of this filesystem!
Because of this some operations may be unavailable.
-------------------- END --------------------

If i do an "ls -l /dev/sd*", only /dev/sda exists. "fdisk -l /dev/sda" 
isn't very friendly:
--------------------BEGIN--------------------

WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util 
fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sda: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000

Disk /dev/sda doesn't contain a valid partition table
-------------------- END --------------------

Any ideas how to copy the partition table that GParted is seeing into 
those first 512 bytes that are blank? I haven't started Googling for an 
answer yet, but will definitely be doing that today.

All my Linux and OpenBSD machines have automated backups. I can't say 
the same for this lone OS X/Ubuntu hybrid. Needless to say, however, if 
i can get everything back i'll figure out a way to start doing backups.

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