ok no worries, will try the nighly way as well, it would seem that stock debian stretch currently is somewhat behind in the mainline kernel updates as well things that replace the old fex seemed more advanced forwards in the more recent mainline kernels e.g. 4.18 and further edit: update ok switched to nightly $ /sbin/swapon NAME       TYPE       SIZE USED PRIO /var/swap  file       128M   0B   -2 /dev/zram1 partition 61.7M   0B    5 /dev/zram2 partition 61.7M   0B