One sanctioned commercial solution is the Cyclades ACS serial console servers (8-port ~$2,000 and 32-port ~$3,000) with separate power strip relay like Startech rackmount server switch (8 outlet ~$440). What if you're just a hobbyist wanting to put some servers away in the closet or basement, but don't want to have to physically be present by the server when there is a problem?
Here is my proposed solution.
- A power over ethernet switch, like Netgear ProSafe GS108T (~$100). The main reason to have power over ethernet is for interfacing with the serial-to-ethernet adapters.
- A Netburner serial-to-ethernet adapter (~$30) with a power over ethernet module (~$8). The adapter has additional analog or digital ports that can be used to drive a relay.
- A pair of solid state relay rated for 120VAC at least 10A input such as Opto 22 120D10 (~$22). This is a SPST (single pole single throw) relay, and will need a pair of them to control one NEMA 5 outlet which has two contacts. Also need to connect these contacts to NEMA 5 plugs (could use a cable like this one, ~$5). Consider using a blade crimp connector.
If you have 8 servers or more, you might as well go for the Startech rackmount server switch.