Updating NetBSD binary packages

["Dirk H. Schulz" <dirk.schulz%kinzesberg.de@localhost>]

This is a newbie question, I know, but I did not find much on that.

I have installed NetBSD 5 from ISO/CD and added 
"PKG_PATH="ftp://ftp.NetBSD.org/pub/pkgsrc/packages/NetBSD/i386/5.0_2009Q1/All"; 
to root's .profile. Then I have installed additional packages using 
pkg_add - that means, I have installed binary packages instead of 
compiling from pkgsrc, as I understand it.

Now I want to update these and the base packages. All documentation on 
updating NetBSD relates to compiling sources, but since I can install 
binary packages there must be a way to update binary packages.
Googling once more I found pkg_chk. The man page states that it checks 
against pkgsrc - that does not sound like tool I am looking for.

Why do I need that?

I want to setup and run several slim NetBSD servers that have only 
installed what they really need. Having to add pkgsrc to each of them is 
just the opposite of that.
And the other method I see (using a NetBSD workstation to manually 
compile update packages and distribute them manually to all servers) 
also seems inappropriate to modern systems management.

Are these thoughts generally un-NetBSD-ish? Or is there some way to 
smoothly update larger amounts of NetBSD servers?

Any hint or help is appreciated.

Dirk