HD Install :: Partition Table Disappeared

Help...

On my frugal hd install, I had four partitions:

sdb1 - ext2 data - 25GB
sdb2 - swap (linux 82) - 1GB
sdb3 - ext2 dsl image -2GB bootable
sdb4 - ext2 data - 8GB

On my last reboot, grub reported that hd1,2 no longer exists and sure enough only sdb1 remains  

Booting from sda, I can see the following in fdisk (expert mode):

Code Sample

Expert command (m for help): p Disk /dev/sdb: 255 heads, 63 sectors, 4462 cylinders Nr AF  Hd Sec  Cyl  Hd Sec  Cyl     Start      Size ID 1 80   1   1    0 254  63 1023         63   71681967 83 2 00   0   0    0   0   0    0          0          0 00 3 00   0   0    0   0   0    0          0          0 00 4 00   0   0    0   0   0    0          0          0 00 Expert command (m for help): v 5404 unallocated sectors

..so it seems as though the four partitions are partially there, but I don't have much idea how to recover the 2nd, 3rd & 4th partitions without losing the data (which seems to be OK in sdb1). Actually, its the data in sdb4 that I really need.

Any suggestions on how I might go about fixing this with fdisk or any other tool would be most welcome...

Edit - additional info:

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# fdisk -l Disk /dev/sdb: 36.7 GB, 36703934464 bytes 255 heads, 63 sectors/track, 4462 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes   Device Boot      Start         End      Blocks   Id  System /dev/sdb1   *           1        4462    35840983+  83  Linux # mount -t ext2 /dev/sdb1 /mnt/sdb1 # df /mnt/sdb1 Filesystem           1K-blocks      Used Available Use% Mounted on /dev/sdb1             24169412  14475840   8465808  64% /mnt/sdb1 # df -h /mnt/sdb1 Filesystem            Size  Used Avail Use% Mounted on /dev/sdb1              24G   14G  8.1G  64% /mnt/sdb1

Thanks for the tips - 'discovered an "awesome" utility gpart
I couldn't compile the source, but the static binary went like this:

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# ./gpart.linux /dev/sdb Begin scan... Possible partition(Linux ext2), size(23979mb), offset(0mb) Possible partition(Linux swap), size(964mb), offset(23979mb) Possible partition(Linux ext2), size(1913mb), offset(24944mb) Possible partition(Linux ext2), size(8142mb), offset(26858mb) End scan. Checking partitions... Partition(Linux ext2 filesystem): primary Partition(Linux swap or Solaris/x86): primary Partition(Linux ext2 filesystem): primary Partition(Linux ext2 filesystem): primary Ok. Guessed primary partition table: Primary partition(1)   type: 131(0x83)(Linux ext2 filesystem)   size: 23979mb #s(49110640) s(63-49110702)   chs:  (0/1/1)-(1023/254/63)d (0/1/1)-(3056/254/61)r Primary partition(2)   type: 130(0x82)(Linux swap or Solaris/x86)   size: 964mb #s(1975992) s(49110705-51086696)   chs:  (1023/254/63)-(1023/254/63)d (3057/0/1)-(3179/254/60)r Primary partition(3)   type: 131(0x83)(Linux ext2 filesystem)   size: 1913mb #s(3919856) s(51086700-55006555)   chs:  (1023/254/63)-(1023/254/63)d (3180/0/1)-(3423/254/59)r Primary partition(4)   type: 131(0x83)(Linux ext2 filesystem)   size: 8142mb #s(16675464) s(55006560-71682023)   chs:  (1023/254/63)-(1023/254/63)d (3424/0/1)-(4461/254/57)r # ./gpart.linux -W /dev/sdb /dev/sdb [same thing with this at the end] Activate which partition (1..4, q to quit) : 3 Write this partition table (y,n) : y * Warning: partition table written, you should reboot now.

..and I'm writing this from the fixed hd  

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Ouch. How did that happen?

dunno, but - I was fighting with a usb stick and fdisk, moved it from my laptop (sdb1) to my old desktop (sdc1) and no doubt the inevitable happened