Linux basic optimization

 

 

Without root, add ordinary users and authorize management through sudo

Change the default remote connection SSH service port and prohibit root user remote connection

Automatically update server time regularly

Configure the yum update source, download and install the rpm package from the domestic update source

Turn off selinux and iptables (if there is wan ip in the iptables working scenario, it should be turned on, except for high concurrency)

Adjust the number of file descriptors, process and file opening will consume file descriptors

Simplified boot auto-start services (sshd, crond, network, rsyslog)

Linux kernel parameter optimization /etc/sysctl.conf, execute sysctl -p to take effect

Change the character set, support Chinese, but it is recommended to use the English character set to prevent the problem of garbled characters, do not use Chinese

Lock critical system files

Lock key system files
chattr +i /etc/passwd /etc/shadow /etc/group /etc/gshadow /etc/inittab
Unlock
chattr -i /etc/passwd /etc/shadow /etc/group /etc/gshadow /etc/ inittab to
see if it is locked
[root@cobub04 ~]# lsattr /etc/passwd
-------------e- /etc/passwd

 

Empty /etc/issue

hide system version
cat /dev/null > /etc/issue or > /etc/issue

 

Kernel parameter optimization

vi /etc/sysctl.cong