1. #!/bin/bash
    2. #author junxi by 
    3. #this script is only for CentOS 7.x
    4. #check the OS
    6. platform=`uname -i`
    7. if [ $platform != "x86_64" ];then 
    8. echo "this script is only for 64bit Operating System !"
    9. exit 1
    10. fi
    11. echo "the platform is ok"
    12. cat << EOF
    13. +---------------------------------------+
    14. |   your system is CentOS 7 x86_64      |
    15. |      start optimizing.......          |
    16. +---------------------------------------
    17. EOF
    19. #添加公网DNS地址
    20. cat >> /etc/resolv.conf << EOF
    21. nameserver 114.114.114.114
    22. EOF
    23. #Yum源更换为国内阿里源
    24. yum install wget telnet -y
    25. mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
    26. wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
    28. #添加阿里的epel源
    29. #add the epel
    30. wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
    31. # rpm -ivh http://dl.Fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-8.noarch.rpm
    33. #yum重新建立缓存
    34. yum clean all
    35. yum makecache
    36. #同步时间
    37. yum -y install ntp
    38. /usr/sbin/ntpdate cn.pool.ntp.org
    39. echo "* 4 * * * /usr/sbin/ntpdate cn.pool.ntp.org > /dev/null 2>&1" >> /var/spool/cron/root
    40. systemctl  restart crond.service
    42. #安装vim
    43. #yum -y install vim
    45. #设置最大打开文件描述符数
    46. echo "ulimit -SHn 102400" >> /etc/rc.local
    47. cat >> /etc/security/limits.conf << EOF
    48. *           soft   nofile       655350
    49. *           hard   nofile       655350
    50. EOF
    51. ### * 表示对所有用户有限，soft指的是当前系统生效的设置，hard表明系统中所能设定的最大值，nofile表示所限制的资源是打开文件的最大数目，65535就是限制的数量
    53. #禁用selinux
    54. sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
    55. setenforce 0
    57. #关闭防火墙
    58. systemctl disable firewalld.service 
    59. systemctl stop firewalld.service 
    61. #set ssh
    62. sed -i 's/^GSSAPIAuthentication yes$/GSSAPIAuthentication no/' /etc/ssh/sshd_config
    63. sed -i 's/#UseDNS yes/UseDNS no/' /etc/ssh/sshd_config
    64. systemctl  restart sshd.service
    66. #内核参数优化
    67. cat >> /etc/sysctl.conf << EOF
    68. vm.overcommit_memory = 1
    69. net.ipv4.ip_local_port_range = 1024 65536
    70. net.ipv4.tcp_fin_timeout = 1
    71. net.ipv4.tcp_mem = 94500000 915000000 927000000
    73. #tcp连接重用
    74. net.ipv4.tcp_tw_reuse = 1
    76. #tcp连接快速回收
    77. net.ipv4.tcp_tw_recycle = 1
    79. #262144允许等待中的监听
    80. net.core.somaxconn = 262144
    82. #这个参数应该设置足够大，以便能在一个共享内存段下容纳下整个的Innodb缓冲池的大小
    83. kernel.shmmax = 4294967295
    85. #告诉linux内核除非虚拟内存完全满了，否则不要使用交换区
    86. #vm.swappiness = 0
    88. net.ipv4.tcp_timestamps = 0
    89. net.ipv4.tcp_synack_retries = 1
    90. net.ipv4.tcp_syn_retries = 1
    91. net.ipv4.tcp_abort_on_overflow = 0
    93. #TCP接收和发送缓冲区默认大小和最大值
    94. net.core.wmem_default = 8388608
    95. net.core.rmem_default = 8388608
    96. net.core.rmem_max = 16777216
    97. net.core.wmem_max = 16777216
    99. #用于减少失效tcp所占用资源的时间
    100. net.ipv4.tcp_keepalive_time = 1200
    101. net.ipv4.tcp_keepalive_probes = 3
    102. net.ipv4.tcp_keepalive_intvl = 30
    104. net.core.netdev_max_backlog = 262144
    105. net.ipv4.tcp_max_orphans = 3276800
    106. net.ipv4.tcp_max_syn_backlog = 262144
    107. net.ipv4.netfilter.ip_conntrack_max = 2097152
    108. net.nf_conntrack_max = 655360
    109. net.netfilter.nf_conntrack_tcp_timeout_established = 1200
    110. ulimit -n 30000
    111. EOF
    112. /sbin/sysctl -p
    114. #vim定义退格键可删除最后一个字符类型
    115. echo 'alias vi=vim' >> /etc/profile
    116. echo 'stty erase ^H' >> /etc/profile
    117. cat >> /root/.vimrc << EOF
    118. set tabstop=4
    119. set shiftwidth=4
    120. set expandtab
    121. syntax on
    122. "set number
    123. EOF
    125. #update soft
    126. yum -y update 
    127. yum -y install vim tree net-tools lrzsz gcc*
    129. cat << EOF
    130. +-------------------------------------------------+
    131. |               optimizer is done            |
    132. |   it's recommond to restart this server !       |
    133. +-------------------------------------------------+
    134. EOF