Really what they're proposing here is a non-modifiable system, where the root is read-only and no user can modify anything important.
Which is nice and all, but that implies a "parent" system that creates and deploys those systems. Which people likely want remote access to.. Probably by sshd...
Which is nice and all, but that implies a "parent" system that creates and deploys those systems. Which people likely want remote access to.. Probably by sshd...