1.linux 安全防止暴力破解
https://www.cnblogs.com/panblack/p/secure_ssh_auto_block.html
查看历史登录记录
sudo lastb
- redhat7或者centos7配置阿里云yum源
cd /etc/yum.repos.d
wget -P . http://mirrors.aliyun.com/repo/Centos-7.repo
sed -i \'s/$releasever/7/g\' Centos-7.repo #因为Centos-7.repo文件中$releasever获取的值和实际路径值不一样，所以手动修改
yum clean all
yum makecache
3.df 格式化
df -h|sed \'1d;/ /!N;s/\\n//;s/ +/ /;\'