Clean up /dev/mapper/docker and release space without shutdown process

Hi i see a lot of response about this but is not clear…

I leave what is the problem about cleaning /dev/mapper in linux using docker…

i have a docker images running wp nginx and mysql… the data of the wp is not much than 10G max 20G
the db is no less than 300mb creating a volumen for that… so the total space using from a disk of 80GB is more or less 30GB

so…

Why after some time the capacity of the disk or the mapper almost reach more the 90% of the hard drive ??

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so to clean that i need to stop docker compose… and up again…

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As you see i recover more space…

so i like to know…

why this happen ???

and Any way or procedure to clean without shut down the process..???

Source: StackOverflow