need help recovering lost partition table

[hank43]

I had a dual boot issue (nt4 & rh7.3) so stupid me executed:
dd if=/dev/zero of=/dev/sda bs=512 count=1

how do i recover my partitions without a backup? i had no luck with gpart, testdisk, and fixdisktable. however, rescuept gave me some decent info.

[root@localhost linux]# /sbin/rescuept /dev/sda
# partition table of /dev/sda
# total size 35566478 sectors
unit: sectors
# 0 MB candidate ext pt (type 5): sectors 1541061- 1541061
# 4001 MB found in ept (type 7): sectors 1541124- 9734210
# 4001 MB extended part ok (type 5): sectors 1541061- 9734210
# 10 MB small fat partition (type 1): sectors 10079654- 10100392
# 0 MB candidate ext pt (type 5): sectors 13109040- 13109040
# retracted
# 55 MB ext2 partition (type 83): sectors 13109040- 13221493
# 2000 MB fat partition (type 6): sectors 13221495- 17318069
# 0 MB candidate ext pt (type 5): sectors 17318070- 17318070
# 1004 MB found in ept (type 83): sectors 17318133- 19374389
# 3004 MB found in ept (type 83): sectors 19374453- 25527284
# 2000 MB found in ept (type 83): sectors 25527348- 29623859
# 133 MB found in ept (type 82): sectors 29623923- 29896964
# 1757 MB found in ept (type 6): sectors 29897028- 33495524
# 1004 MB found in ept (type 6): sectors 33495588- 35551844
# 8903 MB extended part ok (type 5): sectors 17318070- 35551844
/dev/sda0 : start= 1541061, size= 8193150, Id= 5
/dev/sda0 : start= 1541124, size= 8193087, Id= 7
/dev/sda0 : start= 10079654, size= 20739, Id= 1
/dev/sda0 : start= 13109040, size= 112454, Id=83
/dev/sda0 : start= 13221495, size= 4096575, Id= 6
/dev/sda0 : start= 17318070, size=18233775, Id= 5
/dev/sda0 : start= 17318133, size= 2056257, Id=83
/dev/sda0 : start= 19374453, size= 6152832, Id=83
/dev/sda0 : start= 25527348, size= 4096512, Id=83
/dev/sda0 : start= 29623923, size= 273042, Id=82
/dev/sda0 : start= 29897028, size= 3598497, Id= 6
/dev/sda0 : start= 33495588, size= 2056257, Id= 6



from what i can remember i had and the above output:

primary1: 6.4gb ntfs
primary2: 55mb ext3, /boot
primary3: ? not sure if i had a 3rd primary but the 2000 MB fat makes sense

extended:
1004 MB ext3, /
3004 MB ext3, /home
2000 MB ext3, /usr
133 MB swap
1757 MB fat
1004 MB fat

it is a 18.4 gb quantum atlas 10k iii scsi drive. I would really appreciate any tips or advice you can give me to restore the data.

[Sepero]

Sorry to hear about your luck. I had something like this happen recently to myself. Extended partitions seem to be the most difficult for these programs to recover. Here's a good link I found:
http://staff.washington.edu/trav/linux/lost_partition.html

I was dual booting MS XP and Debian. After this happened, I created a new Debian system where XP was. I never 'erased' my old Debian partition, and just the other day I decided to give testdisk another shot. It 'sort-of' found were my old partition was. I used fdisk to recreate the boundaries. After fscking the heck out of the partition, I was actually able to recover some files(others were damaged). Though, before I fscked it, I made a backup by executing
'cat /dev/hda5 | bzip2 > hda5.bz2'

Now I can restore the partition and try fscking it at another size. To restore the partition, type
'bzcat hda5.bz2 > /dev/hda5'

P.S.
After using a program like fdisk, you usually need to reboot to have the new partition sizes recognized by the Linux. The program partprobe will save you from having to reboot.

[hank43]

ok, i got my data back! used fdisk -u and the output from rescuept to recreate the partition table. data has been backed up to another disk

[Sepero]

Congradulations. :D