Linux CentOS 6.9 System Optimization Script

System version
CentOS Release 6.9 (Final)
2.6.32-696.el6.x86_64 x86_64

[[email protected] scripts] # cat optimize.sh
#! / bin / bash
#autbor yuguotianqing QQ 157245227

export PATH = / usr / local / sbin: / usr / local / bin: / sbin: / bin: / usr / sbin: / usr / bin: / root / bin

mkdir -p / server / scripts

#SElinux off Turn off SElinux
sed -i ‘s # SELINUX = enforcing # SELINUX = disabled # g’ / etc / selinux / config && grep "SELINUX = disabled" / etc / selinux / config && setenforce 0

#iptables off Turn off the firewall
/etc/init.d/iptables stop
/etc/init.d/iptables stop
chkconfig iptables off

#Startup service optimization Turn off auto-startup
chkconfig --list | grep 3: on | egrep -v "crond | sshd | network | rsyslog | sysstat" | awk '{print "chkconfig", $ 1, "off"}' | bash && chkconfig --list | grep 3: on

#Add Chinese characters Set Chinese character set
cp / etc / sysconfig / i18n /etc/sysconfig/i18n.ori && echo ‘LANG =" zh_CN.UTF-8 "‘> / etc / sysconfig / i18n && source / etc / sysconfig / i18n && echo $ LANG

#System time synchronization Internet and system time synchronization
echo '#tmime sync by wen at 2017-12-28' >> / var / spool / cron / root && echo '* / 5 * * * * / usr / sbin / ntpdate time.nist.gov> / dev / null 2 > & 1 '>> / var / spool / cron / root && crontab -l

#Enlarge the text descriptor
echo ‘*-nofile 65535’ >> / etc / security / limits.conf && tail -1 /etc/security/limits.conf

#make kernel Kernel Optimization
cat >> / etc / sysctl.conf << EOF
net.ipv4.tcp_fin_timeout = 2
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 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 = 36000
net.ipv4.route.gc_timeout = 100
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_synack_retries = 1
net.core.somaxconn = 16384
net.core.netdev_max_backlog = 16384
net.ipv4.tcp_max_orphans = 16384
net.ipv4.ip_conntrack_max = 25000000
net.nf_conntrack_max = 25000000
net.netfilter.nf_conntrack_max = 25000000
net.netfilter.nf_conntrack_tcp_timeout_established = 180
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120
EOF

#yum Install common service software
yum install lrzsz nmap tree dos2unix nfs-utils rpcbind telnet -y && rpm -aq lrzsz nmap tree dos2unix nc nfs-utils rpcbind telnet, 

Linux CentOS 6.9 system optimization script