Howt to Clear & Drop Memory Cache in Linux
How to Clear RAM Cache in Linux?
purging all cached data
pageCache, dentries, and inodes from the cache memory
sync; echo 3 | sudo tee /proc/sys/vm/drop_caches
remove only dentries and inodes
sync; echo 2 | sudo tee /proc/sys/vm/drop_caches
clear the page cache
sync; echo 1 | sudo tee /proc/sys/vm/drop_caches
check cached memory
free -h