From: utzoo!henry
Newsgroups: net.bugs.4bsd,net.bugs.v7
Title: Re: problems with dump(8) 
Article-I.D.: utzoo.2293
Posted: Tue Jul 20 15:44:12 1982
Received: Tue Jul 20 15:44:12 1982

I can't speak for the 4BSD version of dump, but two independent analyses
that I know about (one mine) have concluded that using V6 or V7 dump(8) 
on a live filesystem is not safe, period.  physics!gill's problem sounds
like the first one we found:  going in through the /dev entries for a file
system bypasses all that nice machinery that makes sure everybody always
has a consistent view of things like inodes and indirect blocks.