Upgrading old RH server

["Ashley M. Kirchner" <ashley pcraft com>]

   We have an old RH7.3 server that holds all of our user accounts.  
I'm in the process of upgrading everything to FC10 and looking at 
/etc/shadow I'm noticing some differences in the way the passwords are 
encrypted/stored.

   RH7.3's string looks like this:
       $1$9cgDnjV/$SLqsoxfwr6tr3o7QkdQ3j1

   Whereas FC10 looks like:
       
$6$KS2xrBPJ$jXiz1pE9Lpcb8sSSU0ZHifeN9wBwc.k7GdWO4KIJ3F2JqEw/1mD7bPO6b4jvRXiyXrQn0noWPfs.0h6/tjKbe0

   I tried simply copying the old shadow file to a new FC10 server and 
it seems to work just fine, however I wonder if I'm not breaking 
something else by doing that.  So, what's the proper way to do this?  I 
really don't want to have to reset everyone's password (at least not 
till they reach their forced expiration.)

   Thanks.

   -- A