Mount operation :Mountdevice mount point information of the file directory;Mount / dev / CDROM / mnt; Umount / mnt
View the log file : log file path : / var / log / log file important information : / var / log / messages --- system operation or service running status information log file; / var / log / Secure --- system user login log file
Optimization software library: command: yum -y install wget;confirm whether optimization download directory: /etc/yum.repos.d/; gnaw at the command: curl-o / etc / yum.repos.dhttp://mirrors.aliyun.com/repo/Centos-7.rep
Important documents etc directory:
firewalld firewall service: closed:
➊ temporary closure :
Command: systemctl STOP firewalld
View: systemctl Status firewalld
Simple view: systemctl IS-the Active firewalld
➋ permanently closed :
命令：systemctl disable firewalld
View: systemctl Status firewalld.service
Simple view: systemctl IS-Enabled firewalld.service
selinux security services: closed
➊ temporary closure :
setenforce
usage: setenforce [ Enforcing | Permissive | 1 | 0 ]
setenforce Enforcing / 1 --- selinux feature is turned on
setenforce Permissive / 0 --- selinux function temporarily closed
➋ permanently closed :
vi /etc/selinux/config
# enforcing - SELinux security policy is enforced.
selinux security policy is enforced - the security policy is enabled
# permissive - SELinux prints warnings instead of enforcing.
selinux output a warning message instead of enforcement - temporarily closed
# disabled - No SELinux policy is loaded.
No selinux policy is loaded - permanent closure policy function
SELINUX = disabled --- permanently closed selinux
Permanent closure of entry into force : reboot the system
Permanent start the program : modified configuration files - reboot the system to wait a long time to reload selinux program
Time System optimization:
➊ automatic synchronization :
A manner : to achieve automatic time synchronization using timedatectl
⑴: Modify zone
timedatectl set-timezone Asia/Shanghai
⑵: On Time synchronization
timedatectl set-ntp 1
⑶: time synchronization software
yum install -y chrony
systemctl start chrony
systemctl enable chrony
Second way : to achieve automatic time synchronization using ntpdate
ntpdate find time server
ntpdate ntp1.aliyun.com
➋ manually modify the time :
Method 1 : use command timedatectl
timedatectl set-time "2019-12-5 12:08"
Second way : using the command date ???
The operating system character Optimization: Modify System Character Encoding:
➊ view the default encoding information :
echo $ LANG
en_US.UTF-8
➋ temporarily modify :
LANG = zh_CN.utf8
➌ support Chinese encoding , as well as information as possible so that the English translation for the Chinese display
zh_CN.gb18030
zh_CN.GB2312
zh_CN.gbk
zh_CN.utf8
➍ permanent modification :
CAT /etc/locale.conf
LANG = "zh_CN.utf8"
➎ temporary permanent modifications are made :
localectl the SET-locale LANG = "zh_CN.gbk"
System remote connection optimization:
vi / etc / ssh / sshd_config --- Remote service profile
UseDNS no --- whether to open the DNS reverse resolution process
GSSAPIAuthentication no --- whether GSSAPI authentication
Restart: systemctl restart sshd
Optimization system prompt:
Special environment variables : PS1
[ \u@ \h \W]\$
[root@backup ~]#
\ u --- represents a log of user information
\ h --- indicates the host name information
\ W --- shows the current path information
Modify the command prompt information :
➊ temporary modifications :
PS1 = '[\ u @ \ h \ w] \ $'
PS1 = '[\ u @ \ h \ W \ t \ $'
➋ permanent modification :
vi / etc / profile
PS1 = '[\ u @ \ h \ W \ t \ $'
③ Modify command prompt Color :
PS1 = '\ [\ e [32; 1m \] [\ u @ \ h \ W \ t] \ $ \ [\ e [0m \]
\ [\ e [32; 1m \] --- string Add color indicates the digital information of different colors bold font information
\ [\ e [0m \] --- stop string following color modification
System Information To view:
Using the System Version Information : centos 7.6
# cat /etc/redhat-release
CentOS Linux release 7.6.1810 (Core)
Using the system kernel information : 3.xx 4.xx
uname -a
Linux backup 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
Hardware View:
CPU
➊ view the file information : / proc / cpuinfo
RAM
➊ view the file information : / proc / meminfo
Disk
➊ Check the mount information : / proc / mounts