定时释放Linux/CentOS缓存

#!/bin/bash
used=`free -m | awk 'NR==2' | awk '{print $3}'`
free=`free -m | awk 'NR==2' | awk '{print $4}'`  

echo "===========================" >> yl_dropcaches.log
date >> yl_dropcaches.log
echo "Memory usage | [Use：${used}MB][Free：${free}MB]" >>  yl_dropcaches.log  

# drop caches when the free memory less than 10G
if [ $free -le 10000 ] ; then
 #sync && echo 1 > /proc/sys/vm/drop_caches
 #sync && echo 2 > /proc/sys/vm/drop_caches
 sync && echo 3 > /proc/sys/vm/drop_caches
 echo "OK" >>  yl_dropcaches.log
else
 echo "Not required" >> yl_dropcaches.log
fi

　　

https://www.cnblogs.com/zxc2man/p/8175952.html

https://blog.csdn.net/e_wsq/article/details/79905221

https://blog.csdn.net/jfb53440/article/details/79171941