I meant running multiple VMs in VirtualBox to simulate a distributed system as an alternative to buying multiple Raspberry Pis, not running Linux in VirtualBox.
The really cool thing, though, about multiple Raspberry Pis is that the systems really are running in parallel, rather than faking it with multitasking. That's definitely worth something in an educational context.
Still, I think there's value in having this cool looking machine to fiddle with over the computer they're used to messing with all the time. I think it likely to engage more.
Technically, a single PC with multi-process program is often enough. I've used this approach when I worked on some cloud game server, worked good, I just needed to make sure service discovery was OK finding multiple server instances on same IP but different ports.
> The really cool thing, though, about multiple Raspberry Pis is that the systems really are running in parallel, rather than faking it with multitasking.
Imho, multitasking is a much cooler feat than parallelism by mere duplication of the CPU. It requires much more engineering effort, e.g. in areas of memory coherence and such. Also, a modern desktop CPU will be an order of magnitude faster than the RPi, so you'll need a lot of them to match performance.
Glib reply: why not?
Serious reply: VirtualBox is available for Windows, macOS & Linux alike, and is free. Surely that's acceptable?