upgrade - what will happen?

[Fekete Zoltán <fekete.zoltan%minux.hu@localhost>]

Hi There,

I've 2 installations of NetBSD 7.2.
One of them is an online multifunction web server, the other one is a backup.

I want to upgrade both to NetBSD 8.0.
I've read the upgrade documentation of the core system, and it's very detailed, no question about it.

However I've a question regarding pkgsrc. There are several own-backed pkgsrc packages (build is performed always on the backup machine, and pkgin is used to update the online server) installed.
If I upgrade the kernel and the core system to 8.0, what will happen to the packages which are still built for 7.2?
Would they work? If not, what's the recommended way to upgrade them?

I really don't have too much time (max. an hour in the night time) to do the upgrade especially on the online server.

Please give your advices.

Thank you in advance,

FeZ