Linux 常用命令

创建用户和组

# 创建用户gremlins和对应的组，并创建用户家目录/home/gremlins
useradd -m gremlins
# 为用户gremlins设置登录密码
passwd gremlins

防火墙[CentOS7]

#查看防火墙状态
systemctl status firewalld.service
#运行上述命令后，如果看到有绿色字样标注的“active（running）”，说明防火墙是开启状态。

#开启防火墙
systemctl start firewalld.service

#关闭防火墙
systemctl stop firewalld.service

禁止 root 账号直接 ssh 登录

# 禁止root账号ssh登录
sed -i 's/#PermitRootLogin yes/PermitRootLogin no/g' /etc/ssh/sshd_config && systemctl restart sshd
sed -i 's/PermitRootLogin yes/PermitRootLogin no/g' /etc/ssh/sshd_config && systemctl restart sshd
# 禁用密码方式登录
sed -i 's/PasswordAuthentication yes/PasswordAuthentication no/g' /etc/ssh/sshd_config && systemctl restart sshd
# 开启公钥方式登录
sed -i 's/#PubkeyAuthentication yes/PubkeyAuthentication yes/g' /etc/ssh/sshd_config && systemctl restart sshd
# 修改SSH端口号，请修改端口号1234为实际需要的端口
sed -i 's/#Port 22/Port 1234/g' /etc/ssh/sshd_config && systemctl restart sshd

给普通用户赋予 sudo 权限

tee /etc/sudoers.d/tmn <<< 'tmn ALL=(ALL)    NOPASSWD: ALL'
chmod 440 /etc/sudoers.d/tmn

添加 LVM 分区

pvscan
pvcreate /dev/sdb
pvs
vgdisplay
vgextend centos /dev/sdb
vgs
lvcreate -L 1T -n data01 centos
lvscan
lvs
mkfs.xfs /dev/centos/data01
mkdir /data01
vim /etc/fstab
mount -a

SSH 公钥登录

sed -i 's/#PubkeyAuthentication yes/PubkeyAuthentication yes/g' /etc/ssh/sshd_config && systemctl restart sshd
# 用户HOME目录权限为700
chmod 700 /home/tmn
chmod 700 /home/tmn/.ssh
chmod 644 /home/tmn/.ssh/authorized_keys

关闭 SELinux

sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config