HD error: BAD SUPER BLOCK

[Robert Neumann]

Hello there,

this is the problem:
I had a machine running FreeBSD 4.7-Stable. There I added a 80GB 
harddisk. This harddrive I wanted to install on my other machine running 
FreeBSD 4.9-Release. This disk is ad6 so I added

	/dev/ad6	/storage	ufs	rw	2	2

to fstab and rebooted.

While booting the kernel the following error came up:
	...
	/dev/ad6: BAD SUPER BLOCK: MAGIC NUMBER WRONG
	/dev/ad6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY
	...
	THE FOLLOWING FILE SYSTEM HAD AN UNEXPECTED INCONSISTENCY
		/dev/ad6 (/storage)
	automatic file system check failed . .  help!
	Enter full path name of shell or RETURN for /bin/sh:

I hit Return and type
	fsck
which give this output:
	...
	** /dev/ad6
	BAD SUPER BLOCK: MAGIC NUMBER WRONG
	/dev/ad6; NOT LABELED AS A BSD FILE SYSTEM (unused)

I searched the intenet and found this way:
	fsck -b 32

which gives this output for /dev/ad6:
	...
	BAD SUPER BLOCK: MAGIC NUMBER WRONG

Now I tried another way I found on the net:

	dd if=/dev/ad6 skip=32 of=/dev/ad6 seek=16 bs=512 count=16

which gives this output:
	16+0 records in
	16+0 records out
	8192 bytes transferred in 0.024632 secs (332576 bytes/sec)

when I want to leave the shell there are still errors until I remove the 
added line in /etc/fstab.

the output of
	fdisk -t ad6
is the following:
	...
	sysid 165,(FreeBSD/NetBSD/386BSD)
	    start 63, size 160071597 (78159 Meg), flag 80 (active)
	        beg: cyl 0/ head 1/ sector 1;
		end: 1023/ head 254/ sector 63;
	...

the output of /stand/sysinstall ->Configure->Fdisk->ad6 is:

Offset		Size(ST)      END   Name   PType  Desc   Subtype  Flags
0                 63	       62     -	    6	unused	 0	
63         160071597	160071659   ad6s1   3	freebsd	 165	  C
160071660      14868	160086527     -	    6	unused	 0	

I don't know what is wrong but I don't want to lose the data.

Any hint is appreciated.


Thanks a lot,
Robert