If your failover doesn&#x27;t take extreme slowdowns into account, you&#x27;ve still screwed up.<p>It&#x27;s more complicated than just turning off swap.  Even without swap, when you run extremely low on memory the page cache will be squeezed to nothing and you&#x27;ll thrash.  And I don&#x27;t think there&#x27;s a way to set a minimum page cache on Linux.<p>So in other words, I would not rely on the OOM killer ever kicking in.<p>In a situation with more memory use over time a small swap can act as a canary, letting you know you&#x27;re nearing a performance drop, while a swapless server could suddenly hit a molasses wall without dying.