I administer Linux servers (different distributions - Ubuntu server, CentOS, Fedora) - physical and virtual machines. Most of them have an unpleasant feature - if in the "physical console" (which is not ssh, and in a hardware monitor with a hardware keyboard, real or remote via iKVM), for a long time you do not "write" from the keyboard, it goes out.
In reality, it looks like this: you approach the server with a physical monitor, you catch it - the monitor shows a black screen. You cling to the keyboard, press any key - the monitor comes to life and the "physical console" becomes visible (if we are talking about a machine without X, it is always visible starting from the OS boot, if there are X, it can be reached via Ctrl + Alt + F1 ). Or you connect to a virtual machine via VNC - and the same, until you touch the keyboard - there is no picture.
We are not talking about the "screensaver", this is the console falling asleep in text mode.
How to wean Linux-hosts from this behavior?