Servers are (probably) starting to drop serial ports | Hacker News Reader

Servers are (probably) starting to drop serial ports

utcc.utoronto.ca

12 pointsingve7 comments

> It's been very reliable so far, but sooner or later it's going to start failing.

It's not going to start to fall. The whole reason why serial port is there is to be the fallback access if everything else. It is a dumb and simple protocol, doesn't need any network to be configured.

I don't understand how serial is instead included in the complexity of networking, easily losing access if you accidentally bring down the interface or forgetting the IP.

You can't debug kernel boot because there is no networking when the kernel just started.

I think it's just obsession on complexity coupled with cutting down cost.

The replacement described involves the IPMI stack - this means that a separate controller on the server is responsible for exposing the serial-over-IP. You should be able to debug the kernel just fine since it operates separate from the main processor/OS installation.

Leaving aside cost, I imagine that the motivating factor is that when you have a large number of servers in a data centre, it is easier to create a network for the IPMI ports so that you can connect to any server's serial console over the network, instead of either having some kind of "crash cart" in the data center, or having to wire up a serial terminal server to the serial port of each system (which largely accomplishes the same thing as IPMI, but requires more hardware and another type of cable).

That also means that a mistake in configuration leaves the server's management port open to the internet.

IPMI is typically exposed over a dedicated network interface port. As another poster has pointed out - you are as likely to screw that up as you are to screw up the configuration of a serial port console server.

The same is true for networked serial consoles.

I guess it all depends on what you call a "server".

Embedded still makes massive use of this communications port...

For servers, I haven't had a genuine need to use real serial for more than 10 years.. but I have needed it for embedded or hardware hacking. There is always a better facility than a plain serial tty over D-Bus serial, and if the server doesn't implement some UI, IPMI or iLO then frankly I wouldn't have bought it.

If only servers had a universal serial bus we could use instead? /s

Reply on news.ycombinator.com