以下是脚本!

#!/bin/bash

used=`free -m | awk ‘NR==2′ | awk ‘{print $3}’`

free=`free -m | awk ‘NR==2′ | awk ‘{print $4}’`

echo “===========================” >> /var/log/mem.log

date >> /var/log/mem.log

echo “Memory usage | [Use:${used}MB][Free:${free}MB]” >> /var/log/mem.log

if [ $free -le 100 ] ; 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” >> /var/log/mem.log

else

echo “Not required” >> /var/log/mem.log

fi

然后加入到计划任务中,,每30分钟执行一次.

echo ‘*/30 * * * * sh /bak/sh/freemem.sh’ >> /var/spool/cron/root

https://teakki.com/p/57dbcb7780f85eac11d53c6a