CentOS-6.X系统基本优化
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关闭Selinux[[email protected] ~]# setenforce 0
[[email protected] ~]# getenforce
Permissive
[[email protected] ~]# sed -i ‘s#SELINUX=enforcing#SELINUX=disabled#g‘ /etc/selinux/config
[[email protected] ~]# grep "SELINUX=disabled" -C 2 /etc/selinux/config
# permissive - SELinux prints warnings instead of enforcing.
# disabled - No SELinux is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of these two values:
# targeted - Targeted processes are protected,关闭Iptables
[[email protected] ~]# /etc/init.d/iptables stop
iptables: Setting chains to ACCEPT: filter [ OK ]
iptables: Flushing firewall rules: [ OK ]
iptables: Unloading modules: [ OK ]
[[email protected] ~]# chkconfig --level 3 iptables off
[[email protected] ~]# chkconfig --list iptables
iptables 0:off 1:off 2:on 3:off 4:on 5:on 6:off设置系统运行级别
[[email protected] ~]# tail /etc/inittab
# Default runlevel. The runlevels used are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
#
id:3:initdefault:设置系统主机名及解析
[[email protected] ~]# vim /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=linux-node1
[[email protected] ~]# hostname linux-node1
[[email protected] ~]# echo "`ifconfig eth0|awk -F"[ :]+" ‘NR==2{print $4}‘` `hostname`" >> /etc/hosts
[[email protected] ~]# tail -1 /etc/hosts
192.168.56.11 linux-node1
[[email protected] ~]# ping linux-node1
PING linux-node1 (192.168.56.11) 56(84) bytes of data.
64 bytes from linux-node1 (192.168.56.11): icmp_seq=1 ttl=64 time=0.596 ms
64 bytes from linux-node1 (192.168.56.11): icmp_seq=2 ttl=64 time=0.187 ms
64 bytes from linux-node1 (192.168.56.11): icmp_seq=3 ttl=64 time=0.188 ms
64 bytes from linux-node1 (192.168.56.11): icmp_seq=4 ttl=64 time=0.195 ms精简开机自启动服务
- for
[[email protected] ~]# for name in `chkconfig --list|grep "3:on"|awk ‘{print $1}‘|egrep -v "crond|network|rsyslog|sshd|sysstat"`;do chkconfig $name off;done
[[email protected] ~]# chkconfig --list|grep "3:on"
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
network 0:off 1:off 2:on 3:on 4:on 5:on 6:off
rsyslog 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sshd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sysstat 0:off 1:on 2:on 3:on 4:on 5:on 6:off- sed
[[email protected] ~]# chkconfig --list|grep "3:on"|awk ‘{print $1}‘|egrep -v "crond|network|rsyslog|sshd|sysstat"|sed -r ‘s#(.*)#chkconfig \1 off#g‘|bash
[[email protected] ~]# chkconfig --list|grep "3:on"
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
network 0:off 1:off 2:on 3:on 4:on 5:on 6:off
rsyslog 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sshd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sysstat 0:off 1:on 2:on 3:on 4:on 5:on 6:off- awk
[[email protected] ~]# chkconfig --list|grep "3:on"|awk ‘{print $1}‘|egrep -v "crond|network|rsyslog|sshd|sysstat"|awk ‘{print "chkconfig " $1 " off"}‘|bash
[[email protected] ~]# chkconfig --list|grep "3:on"
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
network 0:off 1:off 2:on 3:on 4:on 5:on 6:off
rsyslog 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sshd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sysstat 0:off 1:on 2:on 3:on 4:on 5:on 6:offSSH远程连接优化
[[email protected] ~]# cp -a /etc/ssh/sshd_config /etc/ssh/sshd_config_$(date +%F)
[[email protected] ~]# vim /etc/ssh/sshd_config
13 Port 51898
15 ListenAddress 192.168.56.11
21 Protocol 2
122 UseDNS no
42 PermitRootLogin no
81 GSSAPIAuthentication no
[[email protected] ~]# /etc/init.d/sshd restart
Stopping sshd: [ OK ]
Starting sshd: [ OK ]
[[email protected] ~]# netstat -tnlup|grep "51898"|grep -v "grep"
tcp 0 192.168.56.11:51898 0.0.0.0:* LISTEN 2413/sshd
[[email protected] ~]# ps -ef|grep "sshd"|grep -v "grep"
root 1792 1 0 21:20 ? 00:00:01 sshd: [email protected]/0
root 2413 1 0 23:16 ? 00:00:00 /usr/sbin/sshd
[[email protected] ~]# lsof -i:51898
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
sshd 1383 root 3r IPv4 13166 0t0 TCP 192.168.56.11:ssh->192.168.56.1:65190 (ESTABLISHED)
sshd 3043 root 3u IPv4 16606 0t0 TCP 192.168.56.11:ssh (LISTEN)设置系统字符集
[[email protected] ~]# export LANG=en
[[email protected] ~]# echo $LANG
en
[[email protected] ~]# sed -i ‘s#LANG="en_US.UTF-8"#LANG="zh_CN.UTF-8"#g‘ /etc/sysconfig/i18n
[[email protected] ~]# cat /etc/sysconfig/i18n
LANG="zh_CN.UTF-8"
SYSFONT="latarcyrheb-sun16"
[[email protected] ~]# source /etc/sysconfig/i18n
[[email protected] ~]# echo $LANG
zh_CN.UTF-8同步网络时间服务器
[[email protected] ~]# ntpdate 0.pool.ntp.org
30 Aug 15:38:17 ntpdate[2517]: adjust time server 120.25.108.11 offset -0.000251 sec
[[email protected] ~]# hwclock
Tue 30 Aug 2016 11:38:21 PM CST -0.320182 seconds
[[email protected] ~]# crontab -e
####Synchronization Network Time Server####
*/5 * * * * /usr/sbin/ntpdate 0.pool.ntp.org &>/dev/null
[[email protected] ~]# crontab -l
####Synchronization Network Time Server####
*/5 * * * * /usr/sbin/ntpdate 0.pool.ntp.org &>/dev/null设置系统历史命令记录数及登录超时
[[email protected] ~]# export HISTSIZE=100
[[email protected] ~]# export HISTFILESIZE=100
[[email protected] ~]# export HISTTIMEFORMAT="%Y-%m-%d %H:%M:%S "
[[email protected] ~]# export TMOUT=300
[[email protected] ~]# echo $HISTSIZE
100
[[email protected] ~]# echo $HISTFILESIZE
100
[[email protected] ~]# echo $HISTTIMEFORMAT
%Y-%m-%d %H:%M:%S
[[email protected] ~]# echo $TMOUT
300
[[email protected] ~]# vim /etc/profile
HISTSIZE=100
export HISTFILESIZE=100
export HISTTIMEFORMAT="%Y-%m-%d %H:%M:%S "
export TMOUT=300
[[email protected] ~]# source /etc/profile设置系统文件描述符数
[[email protected] ~]# ulimit -n
1024
[[email protected] ~]# ulimit -SHn 65535
[[email protected] ~]# ulimit -n
65535
[[email protected] ~]# echo "* - nofile 65535" >> /etc/security/limits.conf
[[email protected] ~]# tail -1 /etc/security/limits.conf
* - nofile 65535设置系统别名
[[email protected] ~]# alias grep=‘grep --color=auto‘
[[email protected] ~]# alias egrep=‘egrep --color=auto‘
[[email protected] ~]# alias ll=‘ls -l --color=auto --time-style=long-iso‘
[[email protected] ~]# alias vi=‘vim‘
[[email protected] ~]# cat >> /etc/bashrc<<EOF
alias grep=‘grep --color=auto‘
alias egrep=‘egrep --color=auto‘
alias ll=‘ls -l --color=auto --time-style=long-iso‘
alias vi=‘vim‘
EOF
[[email protected] ~]# tail -4 /etc/bashrc
alias grep=‘grep --color=auto‘
alias egrep=‘egrep --color=auto‘
alias ll=‘ls -l --color=auto --time-style=long-iso‘
alias vi=‘vim‘
[[email protected] ~]# source /etc/bashrc更新国内yum源
- aliyun
[[email protected] ~]# cp -a /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo_$(date +%F)
[[email protected] ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
--2016-08-30 15:54:20-- http://mirrors.aliyun.com/repo/Centos-6.repo
Resolving mirrors.aliyun.com... 115.28.122.210, 112.124.140.210
Connecting to mirrors.aliyun.com|115.28.122.210|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2572 (2.5K) [application/octet-stream]
Saving to: “/etc/yum.repos.d/CentOS-Base.repo”
100%[===================================================================================================================>] 2,572 --.-K/s in 0s
2016-08-30 15:54:20 (178 MB/s) - "/etc/yum.repos.d/CentOS-Base.repo" saved [2572/2572]
[[email protected] ~]# yum makecache- epel
[[email protected] ~]# cp -a /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo_$(date +%F)
[[email protected] ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
--2017-04-17 10:14:16-- http://mirrors.aliyun.com/repo/epel-6.repo
Resolving mirrors.aliyun.com... 112.124.140.210, 115.28.122.210
Connecting to mirrors.aliyun.com|112.124.140.210|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1083 (1.1K) [application/octet-stream]
Saving to: “/etc/yum.repos.d/epel.repo”
100%[=====================================================================>] 1,083 --.-K/s in 0s
2017-04-17 10:14:17 (5.47 MB/s) - “/etc/yum.repos.d/epel.repo” saved [1083/1083]
[[email protected] ~]# yum makecache隐藏系统版本信息及设置登录提示语
[[email protected] ~]# > /etc/issue
[[email protected] ~]# > /etc/issue.net
[[email protected] ~]# cat >> /etc/motd<<EOF
Welcome To Join The Keywa Family, Please Save Your Account And Password, If You Have Any Questions, Please Contact Your System Administrator!
Mail: [email protected]
QQ: 12345678
EOF
[[email protected] ~]# cat /etc/motd
Welcome To Join The Keywa Family, Please Save Your Account And Password, If You Have Any Questions, Please Contact Your System Administrator!
Mail: [email protected]
QQ: 12345678调整系统内核参数
[[email protected] ~]# cat >> /etc/sysctl.conf<<EOF
# By LinBin At 2017-04-17
net.ipv4.tcp_fin_timeout = 2
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_keepalive_time = 600
net.ipv4.ip_local_port_range = 4000 65000
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
EOF
[[email protected] ~]# sysctl -p设置grub菜单密码
[[email protected] ~]# grub-md5-crypt
Password:
Retype password:
$1$hz0Px$imRsIcA766L/8uRRwykMW0
[[email protected] ~]# cp -a /boot/grub/grub.conf /boot/grub/grub.conf_$(date +%F)
[[email protected] ~]# vim /boot/grub/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/sda3
# initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
password --md5 $1$hz0Px$imRsIcA766L/8uRRwykMW0
title CentOS 6 (2.6.32-504.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-504.el6.x86_64 ro root=UUID=b26e3928-3456-4d4c-8e0f-142833566be5 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-504.el6.x86_64.img以上是关于CentOS-6.X系统基本优化的主要内容，如果未能解决你的问题，请参考以下文章