How to automatically clear RAM on KVM virtual machines?

Question

KVM

There are several virtual machines (KVM) running on the debian server. After a month of work, the RAM on the server is occupied by 80% or more. After rebooting virtual machines, RAM is used by 40 percent.
Is there any automated way to clear the RAM on virtual machines?

Answer 1

Isn't it more logical to look for what it is filled with? Maybe you have a memory leak there ...
Put the reboot command in the cron, in virtual machines

Answer 2

>Is there any automated way to clear the RAM on virtual machines?
restart only the software that eats up memory.
you can see top/atop.
also, about kernel caching methods: https://www.linuxatemyram.com/
you can add zswap, zram, regular swap.