To my knowledge all modern DCs have out-of-band networks for this sort of thing that provide serial access to the BMC chip, nothing old school about that. Old school is having to submit a ticket to Jerry in the DC to walk the crash cart down to box 55AE, hook up a serial console, run diagnostics, and attach the output back to the ticket. You only have to deal with Jerry occasionally now, usually when the BMC or power rails fail.

> Or if it's a bunch of bare metal machines, hopefully someone old-school in the organization thought to deploy 48/96-port rs232 console serial concentrators and wire them up to the db9 serial port on each physical server. And you didn't disable all local serial tty in your operating config.

In a hacker folklore story this would 100% be the solution. And for some reason they'd have to use an original VT100 that some greybeard had lovingly restored at home.