After an unexplanatory freeze on my Quadra 840 running 1.6R, I had to 
manually reset the machine. Since this has happened once or twice 
before, I expected fsck to be run and be finished in half an hour. 
Unfortunately, fsck immediately exited reporting:

dev/rsd1a: BAD SUPER BLOCK: VALUES IN SUPER BLOCK DISAGREE WITH THOSE 
IN FIRST
ALTERNATE

The filesystem appeared to function normally. I read the man page for 
fsck (couldn't find anything) and then the one for fsck_ffs. I found 
out fsck_ffs -d would give me diagnostic reports. I saw some values 
were replaced by noughts in the alternate super block.

I can't get fsck(_ffs) to repair this problem. Help! ;-)
Thanks very much in advance.

-- 
Best Regards,

Reinier Jonker