nixpkgs/nixos/doc/manual/configuration/profiles/headless.xml

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         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-profile-headless">
 <title>Headless</title>

 <para>
  Common configuration for headless machines (e.g., Amazon EC2 instances).
 </para>

 <para>
  Disables <link linkend="opt-sound.enable">sound</link>, <link linkend="opt-boot.vesa">vesa</link>, serial consoles, <link linkend="opt-systemd.enableEmergencyMode">emergency mode</link>, <link linkend="opt-boot.loader.grub.splashImage">grub splash images</link> and configures the kernel to reboot automatically on panic.
 </para>
</section>