swap分区报警处理

- 日理万妓 2022-03-26 13:12 292阅读 0赞

*  [永久性修改][Link 1]
 *  [怎么释放swap？][swap]
    
     *  [a.查看当前swap分区挂载在哪][a._swap]
     *  [b.关停这个分区][b.]
     *  [c.查看状态][c.]
     *  [d.将swap挂载][d._swap]

# 永久性修改： #

[root@wenwen ~]# vim /etc/sysctl.conf

加入参数：

vm.swappiness = 35

注意：该值默认为60，也就是说，你的内存在使用到100-60=40%的时候，就开始出现有交换分区的使用。通过修改swappiness内核参数，降低系统对swap的使用，从而提高系统的性能。

然后在直接：

[root@wenwen ~]# sysctl -p
    查看是否生效：
    cat /proc/sys/vm/swappiness
    35

一般系统是不会自动释放内存的

关键的配置文件/proc/sys/vm/drop\_caches。这个文件中记录了缓存释放的参数，默认值为0，也就是不释放缓存。他的值可以为0~3之间的任意数字，代表着不同的含义：

*  0 不释放
 *  1 释放页缓存
 *  2 释放dentries和inodes
 *  3 释放所有缓存

# 怎么释放swap？ #

## a.查看当前swap分区挂载在哪 ##

[root@172-1-1-187 ~]# swapon -s
    文件名                          类型            大小    已用    权限
    /dev/dm-1                               partition       2097148 1083776 -1

## b.关停这个分区 ##

> 注意:关停之前一定要保证可用物理内存大于swap的空间,不然你就等着跑路吧

[root@172-1-1-187 ~]# swapoff /dev/dm-1

## c.查看状态 ##

[root@172-1-1-187 ~]# swapon -s

## d.将swap挂载 ##

[root@172-1-1-187 ~]# swapon /dev/dm-1

[Link 1]: https://note.youdao.com/md/preview.html?file=%2Fyws%2Fapi%2Fpersonal%2Ffile%2F068F16F0D5BC44E399B08752B46C2F58%3Fmethod%3Ddownload%26read%3Dtrue%26shareKey%3D8bf32aed0aaadb2201ca708f03b6eed0#%E6%B0%B8%E4%B9%85%E6%80%A7%E4%BF%AE%E6%94%B9
[swap]: https://note.youdao.com/md/preview.html?file=%2Fyws%2Fapi%2Fpersonal%2Ffile%2F068F16F0D5BC44E399B08752B46C2F58%3Fmethod%3Ddownload%26read%3Dtrue%26shareKey%3D8bf32aed0aaadb2201ca708f03b6eed0#%E6%80%8E%E4%B9%88%E9%87%8A%E6%94%BEswap
[a._swap]: https://note.youdao.com/md/preview.html?file=%2Fyws%2Fapi%2Fpersonal%2Ffile%2F068F16F0D5BC44E399B08752B46C2F58%3Fmethod%3Ddownload%26read%3Dtrue%26shareKey%3D8bf32aed0aaadb2201ca708f03b6eed0#a%E6%9F%A5%E7%9C%8B%E5%BD%93%E5%89%8Dswap%E5%88%86%E5%8C%BA%E6%8C%82%E8%BD%BD%E5%9C%A8%E5%93%AA
[b.]: https://note.youdao.com/md/preview.html?file=%2Fyws%2Fapi%2Fpersonal%2Ffile%2F068F16F0D5BC44E399B08752B46C2F58%3Fmethod%3Ddownload%26read%3Dtrue%26shareKey%3D8bf32aed0aaadb2201ca708f03b6eed0#b%E5%85%B3%E5%81%9C%E8%BF%99%E4%B8%AA%E5%88%86%E5%8C%BA
[c.]: https://note.youdao.com/md/preview.html?file=%2Fyws%2Fapi%2Fpersonal%2Ffile%2F068F16F0D5BC44E399B08752B46C2F58%3Fmethod%3Ddownload%26read%3Dtrue%26shareKey%3D8bf32aed0aaadb2201ca708f03b6eed0#c%E6%9F%A5%E7%9C%8B%E7%8A%B6%E6%80%81
[d._swap]: https://note.youdao.com/md/preview.html?file=%2Fyws%2Fapi%2Fpersonal%2Ffile%2F068F16F0D5BC44E399B08752B46C2F58%3Fmethod%3Ddownload%26read%3Dtrue%26shareKey%3D8bf32aed0aaadb2201ca708f03b6eed0#d%E5%B0%86swap%E6%8C%82%E8%BD%BD