新系统基础优化

玥殇

网络设置：
setup设置网络
vi /etc/sysconfig/netwrok-scripts/ifcfg-eth0
删除HWADDR和UUID行
dns：/etc/resolv.conf

linux版本，内核查看
cat /etc/redhat-release
uname -r
uname -m
SELINUX
[root@lufengcentos ~]# sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
[root@lufengcentos ~]# setenforce 0
[root@lufengcentos ~]# getenforce
开机自启动
[root@lufengcentos ~]# for oldboy in `chkconfig --list|grep 3:on|awk '{print $1}'`;do chkconfig --level 3 $oldboy off;done
[root@lufengcentos ~]# for oldboy in crond network rsyslog sshd sysstat ;do chkconfig --level 3 $oldboy on;done
[root@lufengcentos ~]# chkconfig --list|grep 3:on  
防火墙
[root@lufengcentos ~]# /etc/init.d/iptables stop
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Unloading modules:                               [  OK  ]
中文字符
[root@lufengcentos ~]# cat /etc/sysconfig/i18n
LANG="en_US.UTF-8"
SYSFONT="latarcyrheb-sun16"
[root@lufengcentos ~]# cp /etc/sysconfig/i18n /etc/sysconfig/i18n.ori
[root@lufengcentos ~]# echo ' LANG="zh_CN.UTF-8"' >/etc/sysconfig/i18n
[root@lufengcentos ~]# source /etc/sysconfig/i18n
[root@lufengcentos ~]# echo $LANG
时间同步
[root@lufengcentos ~]# echo '#time sync by lufeng @2017-3-14' >>/var/spool/cron/root
[root@lufengcentos ~]# echo '*/5 * * * * /usr/sbin/ntpdate time.nist.gov' >/dev/null2>&1 >>/var/spool/cron/root
[root@lufengcentos ~]# crontab -l
#time sync by lufeng @2017-3-14
*/5 * * * * /usr/sbin/ntpdate time.nist.gov
文件描述符设置
[root@lufengcentos ~]# ulimit -n
1024
[root@lufengcentos ~]# vim /etc/security/limits.conf
*                -        nofile          65535
内核优化
[root@lufengcentos ~]# vi /etc/sysctl.conf
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl =15
net.ipv4.tcp_retries2 = 5
net.ipv4.tcp_fin_timeout = 2
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_orphans = 32768
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_wmem = 8192 131072 16777216
net.ipv4.tcp_rmem = 32768 131072 16777216
net.ipv4.tcp_mem = 786432 1048576 1572864
net.ipv4.ip_local_port_range = 1024 65000
net.ipv4.ip_conntrack_max = 65536
net.ipv4.netfilter.ip_conntrack_max=65536
net.ipv4.netfilter.ip_conntrack_tcp_timeout_established=180
net.core.somaxconn = 16384
net.core.netdev_max_backlog = 16384
[root@lufengcentos ~]# sysctl -p