When I start pihole-FTL , CPU increase and memory usage increase quickly up til it starts to swap and the raspberry become extremely slow.
I had to stop pihole to keep control over my Pi.
I use latest raspbian : 9 (stretch) (installed over the week end)
and latest pi-hole installed over the week end also
I checked what could be done and it seems it starts become worst after adding more Ad list, so I dropped all of them :
root@raspberrypi:/etc/pihole# ls -altr
-rw-r–r-- 1 root root 67895045 Nov 18 02:03 gravity.list
root@raspberrypi:/etc/pihole# > gravity.list
root@raspberrypi:/etc/pihole# systemctl start pihole-FTL
then updated gravity again and checked memory, it seems better, but I am pretty sure this is just because there are far less server to block :
[✓] Your debug token is: qrwhgcmn7p