CnetOS模板机配置及优化过程

#备份现有的网卡配置
[root@tempale ~]# cd /etc/sysconfig/network-scripts/
[root@tempale network-scripts]# cp ifcfg-ens192 netconf.cnf
[root@tempale network-scripts]# mv ifcfg-ens192 ifcfg-eth0

#增改配置文件
TYPE="Ethernet"
PROXY_METHOD="none"
BROWSER_ONLY="no"
BOOTPROTO="static"
IPADDR="10.10.1.20"
GATEWAY="10.10.1.1"
#HWADDR="00:50:56:b6:26:e5" #网卡MAC地址
NETMASK="255.255.255.0"
DNS1="10.10.1.1"
DEFROUTE="yes"
#NM_CONTROLLED="no" #是否支持network程序管理
IPV4_FAILURE_FATAL="no"
IPV6INIT="yes"
IPV6_AUTOCONF="yes"
IPV6_DEFROUTE="yes"
IPV6_FAILURE_FATAL="no"
IPV6_ADDR_GEN_MODE="stable-privacy"
NAME="eth0"
#UUID="7c23c4fb-636a-4bf4-9e9a-c059030f2676" #网卡UUID
DEVICE="eth0"
ONBOOT="yes"
USERDNS="no" #普通用户是否可以操作网卡
#主要修改:网卡IP 掩码 DNS,可选修改:MAC UUID IP获取方式 普通用户是否支持网卡操作


#修改引导配置文件后生成新引导配置文件
[root@tempale ~]# vi /etc/default/grub 
GRUB_CMDLINE_LINUX="net.ifnames=0 biosnames=0 rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb quiet"
[root@tempale ~]# grub2-mkconfig -o /boot/grub2/grub.cfg 


#重启系统
[root@tempale ~]# reboot
[root@tempale ~]# ifconfig 
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.10.1.20  netmask 255.255.255.0  broadcast 10.10.1.255
        inet6 fe80::fd1f:ad80:1c03:f833  prefixlen 64  scopeid 0x20<link>
        ether 00:50:56:b6:26:e5  txqueuelen 1000  (Ethernet)
        RX packets 98  bytes 10123 (9.8 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 104  bytes 10893 (10.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

#修改为aliyun源
[root@template yum]# cd /etc/yum.repos.d/
[root@tempale yum.repos.d]# mv CentOS-Base.repo CentOS-Base.repo.back
[root@tempale yum.repos.d]# curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
#生成缓存
[root@tempale yum.repos.d]# yum makecache
#安装常用软件
[root@tempale yum.repos.d]# yum install -y vim wget git net-tools bash-completion epel-release htop
#安装开发包
[root@tempale ~]# yum groupinstall -y "Development Tools"

#修改epel源
[root@tempale yum.repos.d]# mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup && mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.backup
[root@template ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
[root@tempale yum.repos.d]# yum makecache
[root@tempale yum.repos.d]# yum repolist 
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirrors.aliyun.com
 * extras: mirrors.aliyun.com
 * updates: mirrors.aliyun.com
repo id                                           repo name                                                                                 status
base/7/x86_64                                     CentOS-7 - Base - mirrors.aliyun.com                                                      10,097
epel/x86_64                                       Extra Packages for Enterprise Linux 7 - x86_64                                            13,518
extras/7/x86_64                                   CentOS-7 - Extras - mirrors.aliyun.com                                                       323
updates/7/x86_64                                  CentOS-7 - Updates - mirrors.aliyun.com                                                    1,117
repolist: 25,055

#关闭selinux
[root@tempale yum.repos.d]# sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
[root@tempale ~]# grep 'SELINUX=' /etc/selinux/config 
# SELINUX= can take one of these three values:
SELINUX=disabled

#windows使用xshell生成秘钥,linux生成秘钥如下:
[root@tempale .ssh]# ssh-keygen -t rsa -b 4096 
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):  #保存路径
Enter passphrase (empty for no passphrase):  #秘钥密码
Enter same passphrase again:    #重复秘钥
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
[root@tempale .ssh]# cat id_rsa.pub  #秘钥存放路径
 
#手动导入公钥
[root@tempale .ssh]# cd && mkdir .ssh && cd .ssh
[root@tempale .ssh]# vim authorized_keys  #把公钥复制进去

[root@tempale .ssh]# yum update

#设置最大文件描述符
[root@tempale ~]# vim /etc/security/limits.conf
*               hard    nofile          102400
*               soft    mofile          102400

#内核参数优化
[root@tempale ~]# vim /etc/sysctl.conf
vm.overcommit_memory = 1
net.ipv4.ip_local_port_range = 1024 65000
net.ipv4.tcp_fin_timeout = 1
net.ipv4.tcp_keepalive_time = 1200
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout=120
net.ipv4.tcp_keepalive_time = 2400
net.ipv4.tcp_max_syn_backlog = 8192
net.ipv4.tcp_max_tw_buckets = 5000 
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_abort_on_overflow = 0
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.netdev_max_backlog = 262144
net.core.somaxconn = 20480 
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_max_syn_backlog = 262144
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.nf_conntrack_max = 655360
net.netfilter.nf_conntrack_tcp_timeout_established = 1200
[root@tempale ~]# sysctl -p

#主要的日志文件:dmesg secure messages yum.log
[root@tempale ~]# cd /var/log/
[root@tempale log]# echo "" > messages && echo "" > secure && echo "" > dmesg && echo "" > yum.log

#删除history信息
[root@tempale ~]# echo "" > .bash_history
[root@tempale ~]# history -c