Space issue in docker container

when i am putting more and more content in a docker container which runs aem applicaiton, i get an error -
No space left on device

i already created a sym link for /var/lib/docker to another location which has plenty of space

then why am i still having this space issue…
inside the container i see this location space is mapped with file system :

Question: why data here is getting filled up - and can we not create a new file system instead of /dev/mapper/docker-253:1-7521042-d8blah-blah********

i need to solve this space issue… is there anyone who has a solution