Linux Basic optimization (Mid-term architecture optimization)

• 1. Linux kernel optimization

  First step

  Cat >>/etc/sysctl.conf<<eof
  Net.ipv4.tcp_fin_timeout = 2
  Net.ipv4.tcp_tw_reu SE = 1
  net.ipv4.tcp_tw_recycle = 1
  net.ipv4.tcp_syncookies = 1
  net.ipv4.tcp_keepalive_time =
  Net.i Pv4.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 = +
  Net.ipv4.tcp_syn_retries = 1
  net.ipv4.tcp_synack_retries = 1
  net.core.so Maxconn = 16384
  Net.core.netdev_max_backlog = 16384
  Net.ipv4.tcp_max_orphans = 16384
  iptables
  Net.nf_c Onntrack_max = 25000000
  Net.netfilter.nf_conntrack_max = 25000000
  Net.netfilter.nf_conntrack_tcp_timeout_ established =
  Net.netfilter.nf_conntrack_tcp_timeout_time_wait = +
  Net.netfilter.nf_conntrack_tcp_ timeout_close_wait =
  Net.netfilter.nf_conntrack_tcp_timeout_fin_wait =
  EOF
  

  Step two:

  S Ysctl-p

  
  
  
  

• 2. Adding a dual NIC requires activation

• 3. Turn off the firewall (2 steps)

  sed-i ' s#selinux=enforcing#selinux=disabled#g '/etc/selinux/config
  /etc/init.d/iptables Stop

• 4. Time Synchronization Service (2 steps)

  \ntpdate-u cn.pool.ntp.org
  hwclock-w \ Write hardware time
  HWCLOCK-R \ View Current hardware time
  

  
  Configure Time Synchronization Tasks
  Yum-y install NTP \ Installation time Synchronization tool
  

  
  2. Two ways to synchronize time
  -1. Boot sync
  Vim/etc/rc.d/rc.local
  /usr/sbin/ntpdate-u cn.pool.ntp.org >/dev/null 2>&1; /sbin/hwclock-w
  

  
  -2. Timed Task synchronization
  Vi/etc/crontab
  XX * * * root/usr/sbin/ntpdate-u cn.pool.ntp.org >/dev/null 2>&1; /SBIN/HWCLOCK-W # (Update time write hardware simultaneously)

• 5. Configure the Yum source to add a eper source

  Replace the Yum source
  -1. Clear Yum Source Cache
  Yum Clean All
  -2. Back up the Yum source
  Mv/etc/yum.repos.d/centos-base.repo/etc/yum.repos.d/centos-base.repo.backup
  -3. Replace CentOS 7 Source
  Download new Source: Wget-o/etc/yum.repos.d/centos-base.repo Http://mirrors.aliyun.com/repo/Centos-7.repo
  -4. Generate Cache
  Yum Makecahe
  5. Add Epel Source
  Wget-o/etc/yum.repos.d/epel.repo Http://mirrors.aliyun.com/repo/epel-7.repo

• 6. Streamlined boot-up

  Chkconfig|egrep-v "Crond|sshd|network|rsyslog|sysstat" |awk ' {print "Chkconfig", $, "Off"} ' |bash

• 7. Character Set changes

  Cp/etc/sysconfig/i18n/etc/sysconfig/i18n.ori
  Echo ' lang= ' en_US. UTF-8 "' >/etc/sysconfig/i18n
  source/etc/sysconfig/i18n
  Echo $LANG

• 8. History command, Break time optimization

  echo ' Export tmout=300 ' >>/etc/profile
  echo ' Export histsize=5 ' >>/etc/profile
  echo ' Export histfilesize=5 ' >>/etc/profile
  Tail-3/etc/profile
  . /etc/profile

• 9. Download and install the system basic software

  Yum Install Lrzsz nmap tree Dos2unix nc-y

• 10. Configure the Hosts file (non-optimized project, experiment only)

  Cat >/etc/hosts<<eof
  127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
  :: 1 localhost localhost.localdomain localhost6 localhost6.localdomain6
  172.16.1.5 LB01
  172.16.1.6 LB02
  172.16.1.7 WEB01
  172.16.1.8 WEB02
  172.16.1.9 WEB03
  172.16.1.51 DB01
  172.16.1.31 nfs01
  172.16.1.41 Backup
  172.16.1.61 M01
  172.16.1.62 Jumpserver
  Eof

Linux Basic optimization (Mid-term architecture optimization)