Odd file in /lost+found after softupdate inconsistency in fsck

[Tod McQuillin]

Hi all,

My server froze up tonight after a 2 month uptime running 6.3-PRERELEASE 
from Dec 28 2007.

I had to fsck /home by hand because of an inconsistency fsck couldn't 
repair automatically -- something to do with an unexpected softupdate 
inconsistency.

After that, I ended up with some files in /home/lost+found, one of which 
is quite interesting:

/home/lost+found# ls -lksh
total 24432
24432 -r--------  1 root  operator    40G Mar  5 20:12 #0000005

It is 40G in size but only occupies 24432k on disk, so it is a sparse 
file.  I'm not aware of any sparse files of quite that size on my system 
(or relative sparseness) but it's possible i might overlook one.

But the thing that's interesting to me is the inode number (inode 5) and 
the fact that rm doesn't want me to remove it:

/home/lost+found# rm \#0000005
override r--------  root/operator snapshot for #0000005? n

Is there a magic "shapshot" flag on the file?  Have I somehow damaged my 
ufs2+softupdates filesystem by losing its inode #5 containing snapshot 
data?

Any insights appreciated,
-- 
Tod McQuillin