[Samba] PDC Machine Trust Accounts

[Ben Davis]

I read in the Samba HOWTO Collection that every machine in the domain 
needs to have a corresponding UNIX account.  Does this mean whenever I 
add a machine to the network, I must create a UNIX account for each 
one??  Am I supposed to create Unix accounts for my users as well?  
Doesn't this defeat the purpose of using a centralized authentication 
backend such as LDAP or MySQL?