Zombies everywhere - openvassd zombies

I’m seeing quite a lot of zombie scan processes:

# ps auxwww|fgrep "openvassd" | fgrep -c -v defunct
# ps auxwww|fgrep "openvassd" | fgrep -c defunct

Is there an easy way of finding out what kind of scan operation causes these zombie processes?

i see a lot of zombie processes as well, i’m using more than 20 ip-addresses. I tried to use on target with the set of ip-addresses and a set of targets with one ip-address per target.