CentOS 7 释放内存

[root@myhost001 ~]# free -h
total used free shared buff/cache available
Mem: 974M 433M 66M 8.9M 474M 374M
Swap: 2.0G 107M 1.9G
[root@myhost001 ~]#

sync; echo 3 > /proc/sys/vm/drop_caches 释放包括网页，目录项，索引这3项的内存

[root@myhost001 ~]# echo 3 > /proc/sys/vm/drop_caches
[root@myhost001 ~]#
[root@myhost001 ~]#
[root@myhost001 ~]# free -h
total used free shared buff/cache available
Mem: 974M 414M 484M 8.9M 75M 447M
Swap: 2.0G 107M 1.9G
[root@myhost001 ~]#

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那如何使用yum清理缓存呢？清理yum缓存使用yum clean 命令，yum clean 的参数有headers, packages, metadata, dbcache, plugins, expire-cache, rpmdb, all等。

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释放内存脚本

freemem.sh

#!/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 1000 ] ; 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

定时任务命令

echo "*/30 * * * * root /home/freemem.sh" >> /etc/crontab

作者：iFreek
链接：https://www.jianshu.com/p/1de44c9bedeb
来源：简书