linux 系统优化初始化配置

一、系统优化配置

1、修改yum源  配置国内yum源

　　阿里云yum源地址

#CentOS 5.x
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo
#CentOS 6.x
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
#CentOS 7.x
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

　　163 yum 源地址

# CentOS 5.x
wget http://mirrors.163.com/.help/CentOS5-Base-163.repo
# CentOS 6.x
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo

yum clean all 

yum makecache

yum update

yum upgrade  跟新系统到最新

2、安装软件包

yum -y install lrzsz sysstat 

 

安装后的基本调优 设置

关闭所有的服务

for vick in 'chkconfig --list|grep 3:on|awk 'print $1';do chkconfig --level 3 $vick off;done

启动服务的内容

for vick in crond network syslog sshd;do chkconfig --level 3 $vick on ;done

查看3级别的启动状态

chkconfig --list |grep 3:on

 

更改ssh 登入配置

cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak

vim  /etc/ssh/sshd_config

#####vick######

Port 99                    #修改ssh连接默认端口  

PermitRootLogin no         #禁止root远程登入

PermitEmptyPasswords no    #禁止空密码登入

UseDNS no                  #不使用 DNS

#####vick######

 

sudo  设置

visudo

/root

## Allow root to run any commands anywhere

root       ALL=(ALL)       ALL

vick        ALL=(ALL)       ALL

 

$PATH

vim ~/.bash_profile 

source ~/.bash_profile

echo $PATH 

 

字符集调整

echo 'LANG="zh_CN.GB18030"' > /etc/sysconfig/i18n

source  /etc/sysconfig/i18n

 

服务器时间同步

echo '*/5 * * * * /usr/sbin/ntpdate time.windows.com >/dev/null 2>&1' >> /var/spool/cron/root

 

修改描述符

echo '*      -   nofile        65535'>> /etc/security/limits.conf

ulimit -n     查看描述符字符集大小

 

调整内核参数

vim /etc/sysctl.conf 

net.ipv4.tcp_fin_timeout = 2

net.ipv4.tcp_tw_reuse = 1

net.ipv4.tcp_tw_recycle = 1

net.ipv4.tcp_syncookies = 1

net.ipv4.tcp_keepalive_time = 600

net.ipv4.ip_local_port_range = 4000 65000

net.ipv4.tcp_max_syn_backlog = 16384

net.ipv4.tcp_max_tw_buckets = 360000

net.ipv4.route.gc_timeout = 100

net.ipv4.tcp_syn_retries = 1

net.ipv4.tcp_synack_retries = 1

net.ipv4.ip_conntrack_max = 25000000