Why I Switched from ZRAM to Zswap for Hibernate on NixOS

Swap, ZRAM, Zswap and Hibernate on NixOS

I use swap on my NixOS desktop and laptop to enable suspend-then-hibernate, which first suspends to RAM and then hibernates to disk after a delay. After mistakenly using zramSwap, I switched to boot.zswap.enable with vm.swappiness = 100. I also settled on zstd compression instead of lz4, since a better compression ratio lets more pages stay in memory and reduces disk usage. My final config is just two lines.