Cenos7.5系统优化新装后优化

CenTos7.5系统优化

更改主机名

centos7有一个新的修改主机名的命令hostnamectl

hostnamectl set-hostname --static 主机名

vim /etc/hosts --最后加上你的IP与主机名的绑定

127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 IP 主机名

修改网卡 vim /etc/sysconfig/network-scripts/ifcfg-eth0 --网卡名如果不一样，找到对应的文件就行 BOOTPROTO="static" NAME="eth0" DEVICE="eth0" ONBOOT="yes" IPADDR=10.0.0.1 NETMASK=255.255.255.0 GATEWAY=10.0.0.254 DNS1=114.114.114.114 DNS2=8.8.8.8

#关闭卸载firewalld systemctl stop firewalld.service systemctl disable firewalld.service yum remove firewalld -y yum install iptables-services -y #安装 关闭selinux 临时关闭setenforce 0

sed -i 7s/enforcing/disabled/ /etc/selinux/config 查看getenforce

内核优化

vim /etc/sysctl.conf

#关闭ipv6

net.ipv6.conf.all.disable_ipv6 = 1

net.ipv6.conf.default.disable_ipv6 = 1

#避免放大攻击

net.ipv4.icmp_echo_ignore_broadcasts = 1

#开启恶意icmp错误消息保护

net.ipv4.icmp_ignore_bogus_error_responses = 1

#关闭路由转发

net.ipv4.ip_forward = 0

net.ipv4.conf.all.send_redirects = 0

net.ipv4.conf.default.send_redirects = 0

#开启反向路径过滤

net.ipv4.conf.all.rp_filter = 1

net.ipv4.conf.default.rp_filter = 1

#处理无源路由的包

net.ipv4.conf.all.accept_source_route = 0

net.ipv4.conf.default.accept_source_route = 0

#关闭sysrq功能

kernel.sysrq = 0

#core文件名中添加pid作为扩展名

kernel.core_uses_pid = 1

#开启SYN洪水攻击保护

net.ipv4.tcp_syncookies = 1

#修改消息队列长度

kernel.msgmnb = 65536

kernel.msgmax = 65536

#设置最大内存共享段大小bytes

kernel.shmmax = 68719476736

kernel.shmall = 4294967296

#timewait的数量，默认180000

net.ipv4.tcp_max_tw_buckets = 6000

net.ipv4.tcp_sack = 1

net.ipv4.tcp_window_scaling = 1

net.core.wmem_default = 8388608

net.core.rmem_default = 8388608

net.core.rmem_max = 16777216

net.core.wmem_max = 16777216

#每个网络接口接收数据包的速率比内核处理这些包的速率快时，允许送到队列的数据包的最大数目

net.core.netdev_max_backlog = 262144

#限制仅仅是为了防止简单的DoS 攻击

net.ipv4.tcp_max_orphans = 3276800

#未收到客户端确认信息的连接请求的最大值

net.ipv4.tcp_max_syn_backlog = 262144

net.ipv4.tcp_timestamps = 0

#内核放弃建立连接之前发送SYNACK 包的数量

net.ipv4.tcp_synack_retries = 1

#内核放弃建立连接之前发送SYN 包的数量

net.ipv4.tcp_syn_retries = 1

#启用timewait 快速回收

net.ipv4.tcp_tw_recycle = 1

#开启重用。允许将TIME-WAIT sockets 重新用于新的TCP 连接

net.ipv4.tcp_tw_reuse = 1

net.ipv4.tcp_mem = 94500000 915000000 927000000

net.ipv4.tcp_fin_timeout = 1

#当keepalive 起用的时候，TCP 发送keepalive 消息的频度。缺省是2 小时

net.ipv4.tcp_keepalive_time = 30

#修改防火墙表大小，默认65536

#net.netfilter.nf_conntrack_max=655350

#net.netfilter.nf_conntrack_tcp_timeout_established=1200

#确保无人能修改路由表

net.ipv4.conf.all.accept_redirects = 0

net.ipv4.conf.default.accept_redirects = 0

net.ipv4.conf.all.secure_redirects = 0

net.ipv4.conf.default.secure_redirects = 0

DNS优化（添加对应网络供应商的更佳）

vi /etc/resolv.conf nameserver 8.8.8.8 nameserver 114.114.114.114 nameserver 4.2.2.2 nameserver 172.19.0.6

工具1

yum install wget vim lrzsz

安装 163源 网络源 cd /etc/yum.repos.d/ wget http://mirrors.163.com/.help/CentOS7-Base-163.repo

yum clean all yum makecache fast 安装工具解决密钥问题 cd /etc/pki/rpm-gpg wget https://archive.fedoraproject.org/pub/epel/RPM-GPG-KEY-EPEL-7

常用工具2安装

yum install -y gcc cmake bzip2-devel curl-devel db4-devel libjpeg-devel libpng-devel freetype-devel libXpm-devel gmp-devel libc-client-devel openldap-devel unixODBC-devel postgresql-devel sqlite-devel aspell-devel net-snmp-devel libxslt-devel libxml2-devel pcre-devel mysql-devel pspell-devel libmemcached libmemcached-devel zlib-devel tree htop net-tools

时间同步

#yum install ntp ntpdate -y --安装ntp时间同步相关软件包 #vim /etc/ntp.conf --确认配置文件里有下列的时间同步源 server 0.rhel.pool.ntp.org iburst server 1.rhel.pool.ntp.org iburst server 2.rhel.pool.ntp.org iburst server 3.rhel.pool.ntp.org iburst #systemctl enable ntpd --设置开机自动启动ntpd #systemctl start ntpd --立即启动ntpd服务 #date --确认时间与现在时间一致 #ntpdate 0.rhel.pool.ntp.org --如果还没有同步成功，你可以用此命令手动同步一下 ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime #更改时区为上海

加大打开文件数的限制（open files）

ulimit -n ulimit -a vi /etc/security/limits.conf 最后添加

• soft nofile 1024000
• hard nofile 1024000 hive - nofile 1024000 hive - nproc 1024000

用户进程限制

sed -i 's#4096#65535#g' /etc/security/limits.d/20-nproc.conf #加大普通用户限制 也可以改为unlimited egrep -v "^$|^#" /etc/security/limits.d/20-nproc.conf

•      soft    nproc     65535
  

root soft nproc unlimited 重启让设置生效 reboot 大概就这么多了吧其他的以后再更新