clean buff cache shell script

#!/bin/bash

# 获取总内存大小
total_mem=$(free -m | awk 'NR==2{print $2}')

# 获取buff/cache大小
buff_cache=$(free -m | awk 'NR==2{print $6}')

# 计算buff/cache占总内存的百分比
usage_percentage=$((buff_cache * 100 / total_mem))

echo $total_mem $buff_cache $usage_percentage

# 判断是否超过60%
if [ $usage_percentage -gt 60 ]; then
    echo "Buff/Cache usage is above 60%. Cleaning buff/cache..."

    # 执行清理buff/cache的命令，例如使用sync和echo 3 > /proc/sys/vm/drop_caches
    sync && echo 3 > /proc/sys/vm/drop_caches

    echo "Buff/Cache cleaned."
else
    echo "Buff/Cache usage is below 60%. No action needed."
fi

crontab:

*/30 * * * * /root/clean_buff_cache.sh