Comment by berkes

I always thought I had to add a swap file to avoid crashing with OOM. I wasn't aware of the cold pages overhead.

Sometimes that crashing is what I want: a dedicated server running one (micro)service in a system that'll restart new servers on such crashes (e.g. Kubernetes-alike). I'd rather have it crash immediately rather than chugging along in degraded state.

But on a shared setup like OP shows, or the old LAMP-on-a-vps, i'd prefer the system to start swapping and have a chance to recover. IME it quite often does. Will take a few minutes (of near downtime) but will avoid data corruption or crash-loops much easier.

Basically, letting Linux handle recovery vs letting a monitoring system handle recovery