restore hangs filesystem (more in the running-with-scissors saga)

I've got a suggestion to try a dump after copying a superblock that 
still exists on the disk to the default superblock location.  Is that 
0?  32?  Anyways, that's just a sidebar.

One of the other disks that failed this week (my laptop drive) is less 
sick and the dump succeeded.  I now have a 50 gig dump file.  Good.

Now I have a machine that's been in production in my home network for a 
year or two ... and for this project I added a 250G drive.  The 250G 
drive contains a single partiton and I formatted it UFS 2 with a 65536 
blocksize and a 8192 frag size.  I intend to put big files on this disk.

Anyways, I created a directory on that disk (which also contained the 
filesystem images and dumps ... about 120G in 5 large files), cd'd into 
that directory and ran 'restore -rvf ../dumpfile'.  This went along 
creating directories for awhile and then it stopped for a few momments 
... then sputtered along for another few seconds and then hung.  The 
other disks on the machine were also hung when I tried to access them in 
the shell.

I rebooted, waited for the background fscks to complete and tried 
again.  It appears to be repeatable.

The disk that I'm restoreing is a typical laptop /usr ... it has 
/usr/ports and /usr/src (many directories).

Dave.