CentOS7清理yum缓存和释放内存方法

清理yum缓存

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

yum clean headers #清理/var/cache/yum的headers yum clean packages #清理/var/cache/yum下的软件包 yum clean metadata ...

Linux释放内存

释放网页缓存(To free pagecache):

sync; echo 1 > /proc/sys/vm/drop_caches

释放目录项和索引(To free dentries and inodes):

sync; echo 2 > /proc/sys/vm/drop_caches

释放网页缓存，目录项和索引（To free pagecache, dentries and inodes）:

sync; echo 3 > /proc/sys/vm/drop_caches

下面是我实际的数据。

[root@localhost ~]# free -m    #查看内存 total        used        free      shared  buff/cache   available Mem: 481 224 120 1 136 202 Swap: 1023 283 740 [root@localhost ~]# sync; echo 3 > /proc/sys/vm/drop_caches  [root@localhost ~]# free -m    #从120到186，释放了66m的内存 total        used        free      shared  buff/cache   available Mem: 481 209 186 1 85 222 Swap: 1023 283 740