selfhosting.couchsurfinginteresting discussion on the odd fact that in Linux we have #zram aka #zramswap (compressed swap in memory) and #zswap (compressed swap buffer in memory which decompresses the data before evicting it to a disk-based backing store if memory is getting low enough), without having simple compressed swap on disk:
https://unix.stackexchange.com/questions/740334/how-to-compress-disk-swap
ａｎａｌｏｇ ｒａｃｃｏｏｎ
Manuel 
Chris Vogel