fsck safe in run level 2?

[Hershel Belkin]

Forgive me if this should be obvious, but I'd like to clear up
something...

I have often heard/read that fsck should not be run on a mounted
file system, and further, should never be run while in multi-user
mode.  While I understand the risks involved in attempting to
use fsck to correct errors while in multi-user mode, I have a 
problem understanding why there should be any harm in using fsck
to simply "look" at a mounted file system even while being used!

I can imagine that the fsck results could be incorrect (ie. may
perhaps indicate an error when in fact there is none) due to
disc activity.  But is there any possibility that fsck could
*cause* a problem (again, assuming "-n" responses)??

I'd appreciate some insights to this question.  (BTW, I have often
run fsck's in this mode, only switching to single user mode if
fsck shows any errors, so that I can confirm them as "real".  I have
never experienced any problems, but I'd like to know what others
feel about this).  Thanks!
-- 
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| Hershel Belkin               hp9000/825(HP-UX)|      UUCP: teecs!belkin |
| Test Equipment Engineering Computing Services |     Phone: 416 246-2647 |
| Litton Systems Canada Limited       (Toronto) |       FAX: 416 246-5233 |
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