Yes. You can boot the entire cluster from a single file server running on any other plan 9 machine be it pi, pc, VM, whatever. Each node boots from the same root file system so each node has the same fs view. This is where ndb[1] comes in Though you can change this any way you see fit. Network booting can be accomplished via pxe or a plan 9 kernel on sd with a plan9.ini configured to automatically pull root via tls or tcp.
have a look at thread(2)[2] and enjoy Go like channels and concurrency cleanly built on top of the nice pan 9 c library. You could just use Go but we dont have Go on pi yet, that's a google SOC 2021 project if anyone is interested.
1. http://man.postnix.pw/plan_9/6/ndb
2. http://man.postnix.pw/plan_9/2/thread