Alias Function: configuration file path: / etc / profile ---- configuration variables / environment variables / configuration information alias
command alias information = 'substitute command information'
permanent setting:
VI / etc / Input Profile: alias command information = ' Alternatively command information '
cancel alias:
a: the configuration file or delete annotations permanently cancel alias ---
II: --- with the command operation of the unalias alias canceled
three: the operation command absolute path
/ usr / bin / rm / oldboy / oldboy01.txt
four: in front of the alias plus a crowbar \
=================================== ================= >>
system running file-level
Linux system run level: / etc / inittab
0 run level --- shutdown level poweroff.target
run a single level --- users run level adaptation to crack the system password rescue.target (rescue mode)
2 --- multi-user run level to run level no network multi-user.target
3 run level --- multi-user run level there is a network multi-user.target *** default run level
4 run level --- reserve / did not use multi-user.target
run level 5 --- graphical run level graphical.target
run level --- 6 reboot run level reboot.target
run level View:
centos6: runlevel
centos7: systemctl GET-default
settings run level information:
centos6:
temporary adjustments: init 2 --- configuration to take effect immediately
permanent adjustments:
vi / etc / inittab
the above mentioned id: 3: initdefault: --- permanently set to run level must not be set to 0 or 6
centos7:
systemctl the sET-default TARGET.target
the SET-default multi-user.target systemctl
========================================= ============ >>
software installation:
1) yum yum -y install the system --- install tree / download good, it will automatically delete the installation package.
2) --- binary installation green software after the hard disk installation archive --- decompression can be used directly
3) rpm to install software --- good software program to download .exe / local premise software packages have been downloaded well
4) compile and install the software --- flexible installation example download software installation package, any free installation path (custom installation).
===================================== >> ===============
log file: / var / log
contains two files in / var / log in: messages: record a program or system operation status information OK / error.
: Secure : record user login information.
brute force password system problems: early detection / address of the specified security policy control to do
the log file to view mode: track ways to view
tail -f / var / log / secure --- track changes in real-time view file information
--- displayed before the file header head few lines (the first 10 rows)
head file information -20
tail --- tail / tail lines display file contents (after line 10)
tail -20 file information
===== ================================================ >>
/ proc: collecting server hardware information, hardware information will be recorded to a file
asset information statistics: hardware information assets
CPU hardware information:
CAT / proc / cpuinfo
Model name: Intel (R) Core (TM) i5-4440 CPU @ 3.10GHz - - displays CPU information
processor: 0 --- displaying information on the number of CPU cores
physical id: 0 --- large ones display CPU information (number of stars)
the CPU MHz: 3092.869 --- display CPU clock speed
command alias information = 'substitute command information'
permanent setting:
VI / etc / Input Profile: alias command information = ' Alternatively command information '
cancel alias:
a: the configuration file or delete annotations permanently cancel alias ---
II: --- with the command operation of the unalias alias canceled
three: the operation command absolute path
/ usr / bin / rm / oldboy / oldboy01.txt
four: in front of the alias plus a crowbar \
=================================== ================= >>
system running file-level
Linux system run level: / etc / inittab
0 run level --- shutdown level poweroff.target
run a single level --- users run level adaptation to crack the system password rescue.target (rescue mode)
2 --- multi-user run level to run level no network multi-user.target
3 run level --- multi-user run level there is a network multi-user.target *** default run level
4 run level --- reserve / did not use multi-user.target
run level 5 --- graphical run level graphical.target
run level --- 6 reboot run level reboot.target
run level View:
centos6: runlevel
centos7: systemctl GET-default
settings run level information:
centos6:
temporary adjustments: init 2 --- configuration to take effect immediately
permanent adjustments:
vi / etc / inittab
the above mentioned id: 3: initdefault: --- permanently set to run level must not be set to 0 or 6
centos7:
systemctl the sET-default TARGET.target
the SET-default multi-user.target systemctl
========================================= ============ >>
software installation:
1) yum yum -y install the system --- install tree / download good, it will automatically delete the installation package.
2) --- binary installation green software after the hard disk installation archive --- decompression can be used directly
3) rpm to install software --- good software program to download .exe / local premise software packages have been downloaded well
4) compile and install the software --- flexible installation example download software installation package, any free installation path (custom installation).
===================================== >> ===============
log file: / var / log
contains two files in / var / log in: messages: record a program or system operation status information OK / error.
: Secure : record user login information.
brute force password system problems: early detection / address of the specified security policy control to do
the log file to view mode: track ways to view
tail -f / var / log / secure --- track changes in real-time view file information
--- displayed before the file header head few lines (the first 10 rows)
head file information -20
tail --- tail / tail lines display file contents (after line 10)
tail -20 file information
===== ================================================ >>
/ proc: collecting server hardware information, hardware information will be recorded to a file
asset information statistics: hardware information assets
CPU hardware information:
CAT / proc / cpuinfo
Model name: Intel (R) Core (TM) i5-4440 CPU @ 3.10GHz - - displays CPU information
processor: 0 --- displaying information on the number of CPU cores
physical id: 0 --- large ones display CPU information (number of stars)
the CPU MHz: 3092.869 --- display CPU clock speed
grep -c processor / proc / cpuinfo --- shows the total number of CPU cores server
--- CPU shows the total number of stars server
lscpu
Architecture: the x86_64
CPU-OP MODE (S): 'bit-32, 64' bit-
CPU (s): 4 --- CPU core number
core (s) per socket: 2 --- each CPU core
Socket (s): 2 --- display server has few CPU
memory hardware information
CAT / proc / meminfo
MemTotal : 2028116 kB --- total memory size
MemFree: 1729172 kB --- free memory capacity
MemAvailable: 1705828 kB --- available memory capacity *****
buffers: 2076 kB --- write data buffer capacity use
cached: 91148 kB --- read data buffer capacity use
[root@oldboyedu ~]# free -h
total used free shared buff/cache available
Mem: 1.9G 140M 1.6G 9.5M 151M 1.6G
Swap: 1.5G 0B 1.5G
--- CPU shows the total number of stars server
lscpu
Architecture: the x86_64
CPU-OP MODE (S): 'bit-32, 64' bit-
CPU (s): 4 --- CPU core number
core (s) per socket: 2 --- each CPU core
Socket (s): 2 --- display server has few CPU
memory hardware information
CAT / proc / meminfo
MemTotal : 2028116 kB --- total memory size
MemFree: 1729172 kB --- free memory capacity
MemAvailable: 1705828 kB --- available memory capacity *****
buffers: 2076 kB --- write data buffer capacity use
cached: 91148 kB --- read data buffer capacity use
[root@oldboyedu ~]# free -h
total used free shared buff/cache available
Mem: 1.9G 140M 1.6G 9.5M 151M 1.6G
Swap: 1.5G 0B 1.5G
Disk hardware information
cat / proc / mounts --- see the system disk partition mounted case
/ dev / sda1 / boot xfs rw , seclabel, relatime, attr2, inode64, noquota 0 0
storage device file system mount point type parameter information
[root @oldboyedu ~] # df -h --- partition capacity usage information, and
the Filesystem Size used Avail the use% Mounted ON
/ dev / 2% sda3 99G 97G 1.6G /
devtmpfs 980M 0 980M 0% / dev
tmpfs 991M 0 0 991M % / dev / SHM
tmpfs 991M 9.6M 981m. 1% / RUN
tmpfs 991M 0 991M 0% / SYS / FS / a cgroup
/ dev / sda1 197M 105M 93M 54 is% / Boot
tmpfs 199M 0 199M 0% / RUN / User / 0
system load: the more recognized CPU task, the higher the load
CAT # / proc / loadavg
0.00 0.01 0.05 load value <= total number of server core the CPU
01 02 03
01. The average case load per minute
02. Every five minutes, the average load
03. average load balanced every 15 minutes
w
the Load Average: 0.00, 0.01, 0.05
The averages for System Load The Past. 1,. 5, and 15 minutes.
cat / proc / mounts --- see the system disk partition mounted case
/ dev / sda1 / boot xfs rw , seclabel, relatime, attr2, inode64, noquota 0 0
storage device file system mount point type parameter information
[root @oldboyedu ~] # df -h --- partition capacity usage information, and
the Filesystem Size used Avail the use% Mounted ON
/ dev / 2% sda3 99G 97G 1.6G /
devtmpfs 980M 0 980M 0% / dev
tmpfs 991M 0 0 991M % / dev / SHM
tmpfs 991M 9.6M 981m. 1% / RUN
tmpfs 991M 0 991M 0% / SYS / FS / a cgroup
/ dev / sda1 197M 105M 93M 54 is% / Boot
tmpfs 199M 0 199M 0% / RUN / User / 0
system load: the more recognized CPU task, the higher the load
CAT # / proc / loadavg
0.00 0.01 0.05 load value <= total number of server core the CPU
01 02 03
01. The average case load per minute
02. Every five minutes, the average load
03. average load balanced every 15 minutes
w
the Load Average: 0.00, 0.01, 0.05
The averages for System Load The Past. 1,. 5, and 15 minutes.
================================================== ==== >>
optimization:
1) the user
create a user under a super user: useradd to create a username and password: passwd username
b modify user password (free interaction): - stdin echo "123456" | passwd --stdin useradd
b2 set the password by ordinary users:
requirements: the need for special symbols need case-sensitive digits in length....
C switch user: --- su - user (user switching is not needed in Supervisor mode switch directly, if contrary to other users or superuser password required)
d see if the user is successfully created: --- id user name plus
2) system command prompt
a: environment variables: PS1 = [\ U @ \ H \ W] \ $
[\ U @ \ H \ W] \ $
[root @ oldboyedu ~] #
\ U --- login information system user name
\ h --- display system host name information (abbreviated display)
\ H --- display system host name information ( full display)
\ W --- shows the current location path information (abbreviated display)
\ w --- shows the current path location information (full display)
\ $ --- display command prompt information
# root user login
b: color
\ [\ e [32; 1m \] start to add color specifying information
\ [\ e [0m \] colored working end
export PS1 = '\ [\ e [30; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \ ] ' gray
export PS1 =' \ [\ e [31; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \] ' gray
export PS1 = '\ [\ e [32; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \]' forgive green color
export PS1 = '\ [\ e [33; 1m \] [ \ u @ \ h \ W] \\ $ \ [\ e [0m \] ' yellow
export PS1 =' \ [\ e [34; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \] 'blue
export PS1 =' \ [\ e [35; 0m 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [\] ' purple
export PS1 = '\ [\ e [36; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \]' blue
export PS1 = '\ [\ e [37; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \] ' white
3) yum source:
a plurality of access aliyun image optimization is started warehouse base (Linux based system) of two optimization EPEL
b obtain yum command in the source file has the help in
base: linux system infrastructure software
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos -7.repo
optimization:
1) the user
create a user under a super user: useradd to create a username and password: passwd username
b modify user password (free interaction): - stdin echo "123456" | passwd --stdin useradd
b2 set the password by ordinary users:
requirements: the need for special symbols need case-sensitive digits in length....
C switch user: --- su - user (user switching is not needed in Supervisor mode switch directly, if contrary to other users or superuser password required)
d see if the user is successfully created: --- id user name plus
2) system command prompt
a: environment variables: PS1 = [\ U @ \ H \ W] \ $
[\ U @ \ H \ W] \ $
[root @ oldboyedu ~] #
\ U --- login information system user name
\ h --- display system host name information (abbreviated display)
\ H --- display system host name information ( full display)
\ W --- shows the current location path information (abbreviated display)
\ w --- shows the current path location information (full display)
\ $ --- display command prompt information
# root user login
b: color
\ [\ e [32; 1m \] start to add color specifying information
\ [\ e [0m \] colored working end
export PS1 = '\ [\ e [30; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \ ] ' gray
export PS1 =' \ [\ e [31; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \] ' gray
export PS1 = '\ [\ e [32; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \]' forgive green color
export PS1 = '\ [\ e [33; 1m \] [ \ u @ \ h \ W] \\ $ \ [\ e [0m \] ' yellow
export PS1 =' \ [\ e [34; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \] 'blue
export PS1 =' \ [\ e [35; 0m 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [\] ' purple
export PS1 = '\ [\ e [36; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \]' blue
export PS1 = '\ [\ e [37; 1m \] [\ u @ \ h \ W] \\ $ \ [\ e [0m \] ' white
3) yum source:
a plurality of access aliyun image optimization is started warehouse base (Linux based system) of two optimization EPEL
b obtain yum command in the source file has the help in
base: linux system infrastructure software
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos -7.repo
epel: Extra Packages for Enterprise Linux Enterprise linux package extra
curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
c centos7 popular software download package
yum install -y vim wget nET-tools SL cowsay the Telnet bash-Completion Tree lrzsz
vim - an upgraded version of vi commands, edit the file information
wget - download files or software to download information tools for
net-tools - network-related Kit
telnet - test network service port is normal
bash-completion --- let systemctl behind parameter information with a complete feature
lrzsz - the windows linux host data can be uploaded to the system rz -y
the linux host data can be downloaded to the windows system -y sz
SL - funny
cowsay "content" - funny
curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
c centos7 popular software download package
yum install -y vim wget nET-tools SL cowsay the Telnet bash-Completion Tree lrzsz
vim - an upgraded version of vi commands, edit the file information
wget - download files or software to download information tools for
net-tools - network-related Kit
telnet - test network service port is normal
bash-completion --- let systemctl behind parameter information with a complete feature
lrzsz - the windows linux host data can be uploaded to the system rz -y
the linux host data can be downloaded to the windows system -y sz
SL - funny
cowsay "content" - funny
4) Firewall:
Role: Configuring Security Policy
service status: enabled by default
optimization: Shut down the server
operation:
first check whether the service is turned on:
centos6
/etc/init.d/iptables Status
centos7
systemctl Status firewalld.service
temporarily closed: systemctl stop firewalld. service
open: systemctl start firewalld.service
permanently closed: systemctl disable firewalld.service
open: systemctl enable firewalld.service
SELinux security program optimization:
role: to limit the root user the ability to
check the service status: getenforce
Enforcing --- open state
temporarily closed: root @ oldboyedu scripts] # setenforce
Usage: setenforce [Enforcing | Permissive | 1 | 0]
[root @ oldboyedu scripts] # setenforce 0
permanently closed:
Method One: vim edits
vim / etc / SELinux / config
SELINUX = Disabled
Method Two: sed command to edit the file
sed -i 'S = enforcing the SELINUX # # # Disabled the SELINUX = G' / etc / SELinux / config
. 5) system character: What character: UTF-8 is supported both Chinese GBK Showing
role Description: Chinese information may be displayed to avoid distortion
modified character:
centos6:
temporary modified:
Export LANG = en_US.GBK
permanent modification:
vim / etc / sysconfig / i18n
LANG = "en_US.GBK"
centos7:
temporary modifications: the environment variable LANG
export LANG = en_US.GBK
permanent changes:
Method a:
Vim / etc / Profile
export LANG = en_US.GBK
Method two:
CAT /etc/locale.conf
the LANG = "en_US.GBK"
a command to change the character encoding:
localectl the locale-SET = the LANG ". 8-the en_US.UTF"
. 6) system time:
View time: date
modification method:
automatically synchronize the time information:
the time zone information provided
timedatectl set-timezone Asia / Shanghai
open network time synchronization
timedatectl set-ntp 1
enable time synchronization service
systemctl status chronyd.service
manually synchronize the system time:
yum the install the ntpdate -Y
ntpdate ntp1.aliyun.com
Role: Configuring Security Policy
service status: enabled by default
optimization: Shut down the server
operation:
first check whether the service is turned on:
centos6
/etc/init.d/iptables Status
centos7
systemctl Status firewalld.service
temporarily closed: systemctl stop firewalld. service
open: systemctl start firewalld.service
permanently closed: systemctl disable firewalld.service
open: systemctl enable firewalld.service
SELinux security program optimization:
role: to limit the root user the ability to
check the service status: getenforce
Enforcing --- open state
temporarily closed: root @ oldboyedu scripts] # setenforce
Usage: setenforce [Enforcing | Permissive | 1 | 0]
[root @ oldboyedu scripts] # setenforce 0
permanently closed:
Method One: vim edits
vim / etc / SELinux / config
SELINUX = Disabled
Method Two: sed command to edit the file
sed -i 'S = enforcing the SELINUX # # # Disabled the SELINUX = G' / etc / SELinux / config
. 5) system character: What character: UTF-8 is supported both Chinese GBK Showing
role Description: Chinese information may be displayed to avoid distortion
modified character:
centos6:
temporary modified:
Export LANG = en_US.GBK
permanent modification:
vim / etc / sysconfig / i18n
LANG = "en_US.GBK"
centos7:
temporary modifications: the environment variable LANG
export LANG = en_US.GBK
permanent changes:
Method a:
Vim / etc / Profile
export LANG = en_US.GBK
Method two:
CAT /etc/locale.conf
the LANG = "en_US.GBK"
a command to change the character encoding:
localectl the locale-SET = the LANG ". 8-the en_US.UTF"
. 6) system time:
View time: date
modification method:
automatically synchronize the time information:
the time zone information provided
timedatectl set-timezone Asia / Shanghai
open network time synchronization
timedatectl set-ntp 1
enable time synchronization service
systemctl status chronyd.service
manually synchronize the system time:
yum the install the ntpdate -Y
ntpdate ntp1.aliyun.com