一.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headersyum clean packages#清理/var/cache/yum下的软件包yum clean metadata...
1.yum clean headers #清理/var/cache/yum的headers
2yum clean packages #清理/var/cache/yum下的软件包
3yum clean metadata
4............
1.释放网页缓存(To free pagecache):
echo 1 > /proc/sys/vm/drop_caches
2.释放目录项和索引(To free dentries and inodes):
echo 2 >/proc/sys/vm/drop_caches
3.释放网页缓存，目录项和索引（To free pagecache, dentries and inodes）:
echo 3 >/proc/sys/vm/drop_caches
三.Linux内存查看
[root@localhost ~]# free -m #查看内存
