Centos常规文件作用

一、系统相关的文件

　　1、系统版本文件

[root@master ~]# cat /etc/redhat-release                                            centos查看系统版本
CentOS Linux release 7.5.1804 (Core)
[root@master ~]# cat /proc/version                                                  查看系统版本及内核版本
Linux version 3.10.0-862.el7.x86_64 (builder@kbuilder.dev.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-28) (GCC) ) #1 SMP Fri Apr 20 16:44:24 UTC 2018
[root@master ~]# uname -a                                                           查看系统版本
Linux master 3.10.0-862.el7.x86_64 #1 SMP Fri Apr 20 16:44:24 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
[root@master ~]# file /bin/ls                                                       查看系统位数
/bin/ls: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=c5ad78cfc1de12b9bb6829207cececb990b3e987, stripped
[root@master ~]# getconf LONG_BIT                                                   查看系统位数
64
[root@master ~]# lsb_release -a                                                     查看系统信息，外部命令，需要安装（yum install -y  redhat-lsb）
LSB Version:    :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch
Distributor ID:    CentOS
Description:    CentOS Linux release 7.5.1804 (Core) 
Release:    7.5.1804
Codename:    Core

　　2、系统资源文件

[root@master ~]# cat /proc/cpuinfo                                                  查看系统cpu信息
processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 158
model name    : Intel(R) Core(TM) i5-8500 CPU @ 3.00GHz
stepping    : 10
microcode    : 0xb4
cpu MHz        : 3000.001
cache size    : 9216 KB
physical id    : 0
siblings    : 2
core id        : 0
cpu cores    : 2
apicid        : 0
initial apicid    : 0
fpu        : yes
fpu_exception    : yes
cpuid level    : 22
wp        : yes
 
[root@master ~]# cat /proc/meminfo                                                   查看系统内存信息
MemTotal:        4028432 kB
MemFree:         3175572 kB
MemAvailable:    3633008 kB
Buffers:            2092 kB
Cached:           648380 kB
SwapCached:            0 kB
Active:           303876 kB
Inactive:         384740 kB
Active(anon):      38816 kB
Inactive(anon):    11116 kB
Active(file):     265060 kB
Inactive(file):   373624 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:         38140 kB
Mapped:            24996 kB
Shmem:             11792 kB
Slab:              89092 kB
SReclaimable:      47692 kB
SUnreclaim:        41400 kB
KernelStack:        3712 kB
PageTables:         3560 kB
NFS_Unstable:          0 kB

　　3、操作系统相关文件

[root@master ~]# cat /etc/hostname                                               查看主机名
 master
[root@master ~]# hostname slave                                                  临时修改主机名
[root@master ~]# hostnamectl set-hostname slave                                  永久修改主机名
[root@master ~]# su                                                              马上生效

[root@master ~]# cat /etc/hosts                                                  查看主机dns映射
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
10.0.0.11 master   master.hdp
10.0.0.31 slave1   slave1.hdp
[root@master ~]# cat /etc/sysconfig/network                                      此文件是针对本计算机的，是给计算机起的一个名字，是计算机的一个标识
# Created by anaconda
NETWORKING=yes
HOSTNAME=master.hdp

　　4、网卡信息文件

[root@master ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33                  网卡文件
TYPE="Ethernet"
PROXY_METHOD="none"
BROWSER_ONLY="no"
BOOTPROTO="none"
DEFROUTE="yes"
IPV4_FAILURE_FATAL="no"
IPV6INIT="yes"
IPV6_AUTOCONF="yes"
IPV6_DEFROUTE="yes"
IPV6_FAILURE_FATAL="no"
IPV6_ADDR_GEN_MODE="stable-privacy"
NAME="ens33"
UUID="1dc50805-9702-4486-8d92-35676bd20f07"
DEVICE="ens33"
ONBOOT="yes"
IPADDR="10.0.0.11"
PREFIX="24"
GATEWAY="10.0.0.2"
DNS1="101.198.198.198"
DNS2="8.8.8.8"
IPV6_PRIVACY="no"
[root@master ~]# ip -4 a                                                          查看IP地址
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
inet 10.0.0.11/24 brd 10.0.0.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever

　　5、目录作用

　　　

[root@master ~]# ls /etc/init.d/                             存放服务的启动文件
functions  netconsole  network  README  
[root@master ~]# cat /etc/sysconfig/selinux                  selinux配置文件

# 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 three two values:
# targeted - Targeted processes are protected,
# minimum - Modification of targeted policy. Only selected processes are protected. 
# mls - Multi Level Security protection.
SELINUXTYPE=targeted