The phrase is an old school principle of German server admins. Backups were super expensive back then and rolling back the system after an "upgrade" or "change" did also cost ALOT of money.

The original phrase was altered and used to be a sports thing (from baseball I believe). It used to be "never change a winning team"

[–] CeeBee@lemmy.world 0 points 1 year ago

Ya, I kinda figured that's what you might mean, and in that case it's entirely wrong.

Long uptimes used to be a point of pride for admins with how long they could keep a single boot session running. But these days a long uptime just means very outdated security patches.

"Never touch a running system" is very much the same vein now. You should constantly be touching the system for system maintenance and such.