One thing you'll want to read up on before taking this on (since you mentioned that this is also your mail server) is PostFix. The default mail server on NetBSD 3.x is Sendmail, and 4.0 uses PostFix, which while a lot saner to configure and generally more trim and fit, it is configured very differently, so you may want to have all of your ducks in a row regarding that before you start your upgrade and either be prepared to swim upstream and keep using sendmail, or have a pretty good idea of what you'll need to do to postfix to make it behave as your sendmail used to.
-lars
At 06:40 PM 3/1/2008, Philip wrote:
I read the documentation on the netbsd.org site and only suggests one upgrade method, that is toboot from a NetBSD 4 CD and upgrade that way.The problem is that my broadband firewall / web server / mail server is running NetBSD 3.1 and has no keyboard, no monitor, and no CDROM drive. It lives in the cupboard under my stairs. I only accessit using ssh.Is there no other way? like put a netbsd 4 kernel on the drive and reboot it or somethingBooting from CD is going to cause quite a lot of hassle. thanks for any help, Philip