linux common summary

yum download dependent files

1. Download dependent yum rpm package for offline installation.

    外网装个一样环境的虚机 用
    mkdir /root/1
    yum install cloud-init --downloadonly --downloaddir=/root/1
    yum install cloud-utils --downloadonly --downloaddir=/root/1
    然后把rpm包拷进内网，
    cd /root/1
    yum localinstall * -y
   

Turn off the firewall

1. CentOS7 turn off the firewall

   # 关闭
   systemctl stop firewalld.service
   systemctl disable firewalld.service
   
   # 打开
   systemctl start firewalld.service
   systemctl enable firewalld.service
   

Change the hostname

1. CentOS7 change the hostname, effective immediately, is not lost after restart

   hostnamectl set-hostname 主机名称
   

disk partition

1. Execute shell:

   磁盘分区
   fdisk $mount_point<<EOF
   n
   p
   1
   
   
   w
   EOF
   

Mounting swap partition

1. Execute shell

   swapoff –a
   mkswap $mount_point
   swapon –a
   echo "$mount_point swap swap defaults 0 0" >> /etc/fstab
   
   

ssh refused landing

1. Delete deny list:

   we /etc/hosts.deny

   Delete inside ip