Anonymous asked in Computers & InternetComputer Networking · 1 month ago

Why are server rooms (depicted as) dark and blue-lit?

Whenever you see large servers and server rooms or data centers in movies, commercials (Think Air Force) or pictures in magazines or something, they are always darkened areas with blue lighting, and also the servers themselves have tons of little blue lights on them. I just started studying operating systems and networking so I know very very little, but from what I am learning so far, perhaps it has to do with fiber optics? Is this actually what large servers and supercomputer environments look like? If so, why?

4 Answers

  • Lv 7
    1 month ago

    EVERY computer (home PC, business PC,  or large-scale server) has LED lights on them, indicating things like power state, hard drive activity, or network activity.

    you need to remember that when you are watching a movie or commercial, they are trying to sell you something. they are TRYING to make it look cool.

    ever see the movie Hackers? it was a great film, but the hacking scenes were NOTHING like actual hacking. because watching ACTUAL hacking is actually pretty boring when you don't understand the code they are typing. probably the most accurate hacking i've seen was on Mr. Robot.

    so yes, there are lights on computers, but no, glowing blue LED lighting for ambience is not standard. RGB lighting like that would cost extra, and without a purpose, no big business would knowingly spend extra for that.

  • 1 month ago

    J.R. provided an excellent answer.  J.R. I used to work in seismic too, for Western Geophysical.

    In the networking side of the industry (where I come from) there is an LED associated with each networking cable (interface) on the assorted devices.  

    A typical server rack has a 48+ port Ethernet switch at the top and another at the bottom.  In the middle are 19" horizontally wide chassis' which are filled with vertically mounted server cards (see picture in J.R's reply).  Each of these server cards have one or two Ethernet ports which connect to one or both of the switches. Point being there will be 100s of LEDs in a typical server rack.  A data center will have potentially 100s of racks, 100K+ LEDs.

    In networking we use the color of the LEDs associated with the Ethernet ports to have a meaning.  This is so you can get a quick visual of the network status.  Each port as an LED that indicates an Ethernet state called LNK (or link).  Depending on the "speed" the port is operating at this LED will be different colors.  Typical servers/server racks use 40Gbps Ethernet.  The networking industry has unofficially determined that blue is the color of the LED used with 40Gbps Ethernet (not a hard and fast rule).   So, each of the ports on the Ethernet switches (96+ ports) will have a blue LED illuminated to indicate that there is a 40Gbps LNK signal between each of its ports and the port on the server it is connected to.  The server itself will have a LED to indicate the same going back to the switch.  Newer Ethernet switches have bluetooth capability for management purposes, these will also have an associated blue LED to indicate activity on bluetooth.  Point being that 1000s of tiny blue LEDs is the source of the blue illumination you are seeing.

    Most of the time these 40Gbps Ethernet links are using fiber optics.  However the light from fiber only goes in/out of the very ends of the fiber which are inside connectors that are plugged into the Ethernet switch or server.  So yes, there is lots of fiber optics in a data center, but none of it is the source of the light you are asking about.

    Another thing to be aware of is that these data centers are so loud inside, due to all the fans in the equipment, that people only go in there if absolutely necessary.  They sound like a huge hive full with very angry bees inside.  

  • BigE
    Lv 7
    1 month ago

    I have been in a fair amount of server rooms and none of them have blue light.  Some are dim until you find the light switch or trigger the motion sensor.

    Yes, it looks like that, racks of servers and switches flashing lights. Just not the blue light.

    Before we hid network cables in raised floor.  Nowadays, we run cable trays above the racks.  Raised floors tend to get tangled and you have to remove tiles to see what you have.

    Power is usually still under raised floor.

  • 1 month ago

    My background is processing seismic data which is one of the biggest data crunchers around, and computer centres are very similar to the huge google , amazon etc centres.

    Servers themselves are very small and because you need thousands (literally) they are packed into rooms. Servers have evolved from being 1U (about 1.5 inches high) and 19 inches wide to fit into standard racks, to having multiple servers approximately paperback size packed into the racking.

    All these individually have LED indicators for one thing or another, power/status, network, so you do see lots of lights.

    The network backbone connects thousands of these servers together, so network equipment will have indicator lights for each network connection.

    That's why you have so many lights.

    Why are they usually dark ? - because you don't need people in them. People only come in to fix things.

    Yes, fibre optic connections are extensively used to connect disk farms and networks, but but these are point to point connections, you don't see light escaping !

    This is a small section of servers. Each has an RJ45 network with indicator leds, and server shows power/status leds

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