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  • Linux系统优化

    Linux系统优化
    [root@renjia ~]# echo "yanjin"|passwd --stdin jinyan
    visudo
    root    ALL=(ALL)       ALL
    renjia  ALL=(ALL)       NOPASSWD: ALL
    leader    ALL=(ALL)       ALL

    server time

    1.yum源

    2.安装必要的软件包

    3.关闭SELINUX
    [root@renjia ~]# vim /etc/selinux/config 
    SELINUX=disabled
    [root@renjia ~]# getenforce  
    Enforcing
    [root@renjia ~]# setenforce 0
    [root@renjia ~]# getenforce  
    Permissive

    /etc/init.d/iptables stop

    [root@renjia ~]# mkdir -p /server/scripts
    [root@renjia ~]# cd /server/scripts/
    [root@renjia scripts]# vim del.sh
    [root@renjia scripts]# ll
    总用量 4
    -rw-r--r-- 1 root root 50 12月 26 13:12 del.sh

    4.runlevel init 0~6
    [root@renjia ~]# runlevel 
    N 3
    cat /etc/inittab
    setup
    ntsysv

    刚装完系统时保留服务:
    crond
    network
    sshd
    syslog
    脚本管理开机自启动的服务:
    LANG=en
    for jinyan in `chkconfig --list|grep 3:on|awk '{print $1}'`;do chkconfig --level 3 $jinyan off;done
    for jinyan in crond network syslog sshd ;do chkconfig --level 3 $jinyan on;done
    chkconfig --list|grep 3:on

    内核优化
    vi /etc/sysctl.conf
    net.ipv4.tcp_fin_timeout = 2
    net.ipv4.tcp_tw_reuse = 1
    net.ipv4.tcp_tw_recycle = 1
    net.ipv4.tcp_syncookies = 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
    #iptables
    net.ipv4.ip_conntrack_max = 25000000
    net.ipv4.netfilter.ip_conntrack_max=25000000
    net.ipv4.netfilter.ip_conntrack_tcp_timeout_established=180
    net.ipv4.netfilter.ip_conntrack_tcp_timeout_time_wait=120
    net.ipv4.netfilter.ip_conntrack_tcp_timeout_close_wait=60
    net.ipv4.netfilter.ip_conntrack_tcp_timeout_fin_wait=120

    sysctl -p

    /etc/init.d/iptables start

    linux定时任务Crond之服务器同步时间
    [root@jinyan ~]# /usr/sbin/ntpdate time.windows.com
    26 Dec 12:42:45 ntpdate[2929]: step time server 64.4.10.33 offset -28179.740945 sec
    [root@jinyan ~]# date
    Thu Dec 26 12:43:04 CST 2013
    [root@jinyan ~]# /sbin/ntpdate time.windows.com
    26 Dec 12:44:34 ntpdate[2934]: adjust time server 65.55.56.206 offset -0.036207 sec

    crontab -e
    #del file
    00 00 * * 6 /bin/sh /server/scripts/del.sh >/dev/null 2>&1
    #sync sys time by jinyan at 2013-12-26
    */5 * * * * /sbin/ntpdate time.windows.com >/dev/null 2>&1
    crontab -l
    #del file
    00 00 * * 6 /bin/sh /server/scripts/del.sh >/dev/null 2>&1
    #sync sys time by jinyan at 2013-12-26
    */5 * * * * /sbin/ntpdate time.windows.com >/dev/null 2>&1




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  • 原文地址:https://www.cnblogs.com/sanyuanempire/p/6169068.html
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