NetBSD netboot with maximal cross-architecture sharing

[Chris Hanson <cmhanson%eschatologist.net@localhost>]

Recently I set up SunOS 4.1 to netboot on both Sun-3 and Sun-4 systems.

I found the SunOS scheme for doing this interesting: To support sharing common files among netbooted systems, including in heterogeneous networks, SunOS separates static from varying content, where the latter is primarily located in the netbooted systems’ root. Furthermore, to support multiple architectures, per-architecture binaries and data are also distinct, and everything is wired together with a semi-standard set of symbolic links.

Meanwhile, NeXT didn’t separate per-architecture content (since they supported multi-architecture binaries) but they did put all of the per-system varying content in /private and had symlinks from /var -> /private/var, /etc -> /private/etc, and /tmp -> /private/temp so the shared root could be read-only.

And of course, on both systems, network home directories can be shared easily.

Are there any documented best practices for setting NetBSD up in this way? If I want to set up (say) NetBSD-current to netboot on several older systems with different architectures, I could naïvely just create a distinct root for each system, but I’d really like to share what I can (beyond home directories) since so much of the OS content will be the same.

  -- Chris