9.28 linux系统基础优化
- 关闭SELinux(是美国安全局对强制访问的实现）功能
[root@wen ~]# sed -i ‘s#SELINUX=enforcing#SELINUX=disabled#g‘ /etc/selinux/config #使用sed + i 命令修改 [root@wen ~]# grep "SELINUX=disabled" /etc/selinux/config #grep查看 SELINUX=disabled [root@wen ~]# cat /etc/selinux/config # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - No SELinux policy is loaded. SELINUX=disabled # SELINUXTYPE= can take one of these two values: # targeted - Targeted processes are protected, # mls - Multi Level Security protection. SELINUXTYPE=targeted 以上重启生效，生产环境不能重启 用以下命令不用重启 [root@wen ~]# getenforce Enforcing [root@wen ~]# setenforce usage: setenforce [ Enforcing | Permissive | 1 | 0 ] [root@wen ~]# setenforce 0 [root@wen ~]# getenforce Permissive
- 运行级别
[root@wen ~]# cat /etc/inittab # inittab is only used by upstart for the default runlevel. # # ADDING OTHER CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM. # # System initialization is started by /etc/init/rcS.conf # # Individual runlevels are started by /etc/init/rc.conf # # Ctrl-Alt-Delete is handled by /etc/init/control-alt-delete.conf # # Terminal gettys are handled by /etc/init/tty.conf and /etc/init/serial.conf, # with configuration in /etc/sysconfig/init. # # For information on how to write upstart event handlers, or how # upstart works, see init(5), init(8), and initctl(8). # # 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 #桌面 # 6 - reboot (Do NOT set initdefault to this) # id:3:initdefault: [root@wen ~]# grep 3:initdefault /etc/inittab #调整运行级别，默认3，可以调成其他 id:3:initdefault: [root@wen ~]# runlevel #查看当前级别 N 3 [root@wen ~]# init 0 #切换运行级别
- 关机
shutdown（halt） init0 参数 -r reboot after shutdown -h halt or power off after shutdown shutdown -h 10 #10分钟后关闭 shutdown now #马上 poweroff #关闭电源 *关闭防火墙 [root@wen ~]# /etc/init.d/iptables stop #临时关闭 iptables：将链设置为政策 ACCEPT：filter [确定] iptables：清除防火墙规则： [确定] iptables：正在卸载模块： [确定] [root@wen ~]# /etc/init.d/iptables status #查看状态 iptables：未运行防火墙。 [root@wen ~]# /etc/init.d/iptables restart # 重启防火墙 iptables：应用防火墙规则： [确定] [root@wen ~]# chkconfig iptables off #开机也不启动了
- linux中文显示设置等
*中文显示设置
[root@wen ~]# echo ‘LANG="zh_CN.UTF-8“‘ > /etc/sysconfig/i18n
[root@wen ~]# cat /etc/sysconfig/i18n
LANG="zh_CN.UTF-8“
[root@wen ~]# echo $LANG
zh_CN.UTF-8
同时调整ssh客户端
*设置账号超时时间
[root@wen ~]# export TMOUT=5 #5秒后关机 （临时生效）
[root@wen ~]# timed out waiting for input: auto-logout
*设置命令行历史记录
[root@wen ~]# history -c #清除所有历史记录
[root@wen ~]# history #查看历史记录
1 history
[root@wen ~]# echo 1
1
[root@wen ~]# echo 2
2
[root@wen ~]# echo 3
3
[root@wen ~]# echo 4
4
[root@wen ~]# echo 5
5
[root@wen ~]# history -d 3 #删除指定行记录
[root@wen ~]# history
1 history
2 echo 1
3 echo 3
4 echo 4
5 echo 5
6 history -d 3
7 history
[root@wen ~]# !6 #执行某行历史命令
history -d 3
[root@wen ~]# export HISTSIZE=5 #控制历史记录记录数量（临时生效）#永久生效放在/etc/profile文件下，然后source以下/etc/profile
[root@wen ~]# history
5 history
6 echo
7 history -d 3
8 export HISTSIZE=5
9 history
[root@wen ~]# cat ~/.bash_history #即使控制了在根目录下还有
[root@wen ~]# export HISTORYSIZE=5 #命令行命令对应文件的记录数
*隐藏版本信息
[root@wen ~]# cat /etc/issue
CentOS release 6.7 (Final)
Kernel \r on an \m
[root@wen ~]# > /etc/issue
[root@wen ~]# cat /etc/issue.net
CentOS release 6.7 (Final)
Kernel \r on an \m
[root@wen ~]# >/etc/issue.net
[root@wen ~]# cat /etc/issue
[root@wen ~]#
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原文：https://blog.51cto.com/wenyule/2951996