vim /etc/sysconfig/network-scripts/ifcfg-ens33  

DEVICE=eth0

ONBOOT=yes

IPADDR=192.168.1.100

NETMASK=255.255.255.0

GATEWAY=192.168.1.2

DNS1=192.168.1.2

DNS2=233.5.5.5

sed -i 's/rhgb/net.ifnames=0 biosdevname=0 &/' /etc/default/grub


grub2-mkconfig -o /boot/grub2/grub.cfg


mv /etc/sysconfig/network-scripts/ifcfg-ens33 /etc/sysconfig/network-scripts/ifcfg-eth0

init 6

yum -y install wget
wget -O /etc/yum.repos.d/CentOS-Base.repo https://repo.huaweicloud.com/repository/conf/CentOS-7-reg.repo

yum install -y  \
tree telnet lrzsz wget ntpdate vim  nc namp dos2unix  tcpdump pstree \
expect sshpass elinks unzip  psmisc \
lsof net-tools htop iproute  bridge-utils \
bind-utils nscd systemd-devel traceroute \
gcc gcc-c++ make cmake libaio zlib-devel pcre-devel pcre  \
psmisclsof sysstat yum-utils \
bash-completion openssl openssl-devel  \
zip bash-c lvm2 iotop bc glibc glibc-devel libevent libevent-devel \
jq psmisc vim net-tools telnet yum-utils device-mapper-persistent-data lvm2 git

systemctl disable --now firewalld 
systemctl disable --now dnsmasq
systemctl disable --now NetworkManager

setenforce 0
sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/sysconfig/selinux
sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/selinux/config


swapoff -a && sysctl -w vm.swappiness=0
sed -ri '/^[^#]*swap/s@^@#@' /etc/fstab

方法一：
rpm -ivh http://mirrors.wlnmp.com/centos/wlnmp-release-centos.noarch.rpm
yum install ntpdate -y
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo 'Asia/Shanghai' >/etc/timezone
ntpdate time2.aliyun.com
# 加入到crontab
*/5 * * * * /usr/sbin/ntpdate time2.aliyun.com

方法二：
yum -y install chrony
systemctl start chrony
systemctl enable chrony

root soft core unlimited
root hard core unlimited
root soft nproc 1000000
root hard nproc 1000000
root soft nofile 1000000
root hard nofile 1000000
root soft memlock 32000
root hard memlock 32000
root soft msgqueue 8192000
root hard msgqueue 8192000
* soft core unlimited
* hard core unlimited
* soft nproc 1000000
* hard nproc 1000000
* soft nofile 1000000
* hard nofile 1000000
* soft memlock 32000
* hard memlock 32000
* soft msgqueue 8192000
* hard msgqueue 8192000

cd /root
wget http://193.49.22.109/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-devel-4.19.12-1.el7.elrepo.x86_64.rpm
wget http://193.49.22.109/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-4.19.12-1.el7.elrepo.x86_64.rpm

yum -y localinstall kernel-ml-*

grub2-set-default  0 && grub2-mkconfig -o /etc/grub2.cfg

grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"

grubby --default-kernel

uname -a
www.guoguo.com 4.19.12-1.el7.elrepo.x86_64 #1 SMP Fri Dec 21 11:06:36 EST 2018 x86_64 x86_64 x86_64 GNU/Linux

net.ipv4.ip_forward = 1
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
kernel.sysrq = 0
kernel.core_uses_pid = 1
net.ipv4.tcp_syncookies = 1
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.shmmax = 68719476736
kernel.shmall = 4294967296
net.ipv4.tcp_max_tw_buckets = 10000
net.ipv4.tcp_sack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_rmem = 4096 87380 4194304
net.ipv4.tcp_wmem = 4096 16384 4194304
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.netdev_max_backlog = 262144
net.core.somaxconn = 262144
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_syn_retries = 1
#net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_fin_timeout = 1
net.ipv4.tcp_keepalive_time = 30
net.ipv4.ip_local_port_range = 1024 65535
net.core.somaxconn = 512
vm.overcommit_memory = 1