But doesn't setting swappiness to zero means the OS ignores the kernel algorithm for swapping? Wouldn't that effectively mean that swap never happens unless the kernel parameters are told not to use the algorithm?No, I meant Linux as that's what we're talking about with this router. I've spent a lot of time in my career fine tuning virtual memory and swap on Solaris, Unixware, AIX, etc. (even IBM mainframes) and they each have their own subtle differences. But regardless of that the OP's router shouldn't be failing to swap when required.