Linux memory usage

#check total %

ps aux | awk ‘{sum +=$4}; END {print sum}’

#check total mem

ps aux | awk ‘{sum +=$5}; END {print sum}’

#sort

ps -auxf | sort -nr -k 4 | head -5

#free mem checking

free -t -m

#release cache

echo 3 > /proc/sys/vm/drop_caches