Today I finally found the time to update my home server from NetBSD 3.1_STABLE to 4.0_BETA2. As usual the update went off without major hitches. I booted the 4.0_BETA2 kernel into single user mode and was pleasantly surpised that it automatically found the root filesystem on the hardware RAID. NetBSD 3.x kernels required a hardwired root filesystem to boot on my server.
Updating the userland was the next task: I extracted the base distribution binary sets, used postinstall(8) to handle most of the necessary changes and fixed the rest (missing users and groups) manually. In addition I replaced all installed packages with 4.0_BETA2 binary packages built on another machine a few days ago. After updating the boot blocks I rebooted the machine again and allowed it proceed to multiuser mode uninterrupted.
Most services worked without problems. Sendmail didn’t start because I hadn’t updated its startup scripts, Postfix tried to start because I hadn’t disabled it. I corrected both issues and my server has been working fine ever since (which is admittedly only a few hours at the moment). So far I had not much time to play with the new features. But I managed at least to switch the /tmp filesystem from MFS to tmpfs.
My next home server improvement project is to replace Sendmail with Postfix. But that will require more time and studying of the Postfix book to complete the configuration files.