LAMP集群项目二 初始化系统

1.关闭防火墙

/etc/init.d/iptables stop

chkconfig iptables off

 

2.关闭selinux

cat /etc/selinux/config #查看状态

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

setenforce 0  #关闭selinux

getenforce     #查看selinux状态

 

3.添加用户

useradd oldboy

id oldboy

echo "123456" | passwd --stdin oldboy && history -c

 

4.更新yum源(souhu源好像没有CentOS6 )

cd /etc/yum.repos.d/

wget http://mirrors.163.com/.help/CentOS6-Base-163.repo

 

5.更新系统

rpm --import /etc/pki/rpm-gpg/PRM-GPG-KEY*

yum upgrade

 

6.安装必要的软件

yum install sysstat -y  # sysstat软件包，包含监测系统的一组工具

 

7.精简开机启动项(虚拟机测试无法开机)

for a in `chkconfig --list | grep "3:on" | awk '{print $1}' | grep -vE "crond|network|sshd|rsyslog"`;do chkconfig $a off; done

 

8.更改ssh配置

cp /etc/ssh/sshd_config /etc/ssh/sshd_config.ori

sed -i 's%#Port 22%Port 52113%' /etc/ssh/sshd_config

sed -i 's%#PermitRootLogin yes%PermitRootLogin no%'

sed -i 's%#PermitEmptyPasswords no%PermitEmptyPasswords no%'

sed -i 's%#UseDNS yes%UseDNS no%' /etc/ssh/sshd_config

egrep "UseDNS|52113|RootLogin|EmptyPass" /etc/ssh/sshd_config

 

9.普通用户加入sudo管理

visudo  #相当于编辑/etc/sudoer

cp /etc/sudoers /etc/sudoers.ori

echo "oldboy  ALL=(ALL) ALL" >>/etc/sudoers

tail -1 /etc/sudoers

 

10.修改字符集显示(测试会码)

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

source /etc/sysconfig/i18n

echo $LANG

 

11.定时任务校准时间（虚拟机需要界面上修改时区，校准时间的地址）

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

crontab -l

 

12.加大文件描述符

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

 

#重新登录后生效

ulimit -n

tail -1 /etc/security/limits.conf

 13.内核参数调优

cp /etc/sysctl.conf /etc/sysctl.conf.`date +"%Y-%m-%d_%H-%M-%S"` #备份
cat>>/etc/sysctl.conf<<EOF
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 2
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_max_orphans = 3276800
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem=4096 87380 16777216
net.ipv4.tcp_wmem=4096 65536 16777216
net.core.netdev_max_backlog =  32768
net.core.somaxconn = 32768
net.ipv4.tcp_syncookies=1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout=1
net.ipv4.tcp_keepalive_time=1200
net.ipv4.tcp_max_syn_backlog = 65536
net.ipv4.ip_local_port_range = 1024  65535
EOF 
cat /etc/sysctl.conf
sysctl -p  #参数生效

 注意：