Chapter 1 / proc directory
1.1 /proc/cpuinfo
Cpu information system
[root@nfsnobody ~]# cat /proc/cpuinfo 一般常用的是 lscpu
processor :0 第几个核心 此处表示第一个
vendor_id : GenuineIntel
cpu family :6
model :60
model name :Intel(R) Core(TM) i5-4200H CPU @ 2.80GHz
stepping :3
microcode :34
cpu MHz :2793.547
cache size :3072 KB
physical id :0第几颗CPU（物理） 此处表示第一个
###以下还有信息 但是不常用 不再显示
cat/proc/cpuinfo 一般常用的是 lscpu
[root@nfsnobody ~]# lscpu 查看cpu的信息1.2 /proc/meminfo
System Memory Information
[root@nfsnobody ~]# cat /proc/meminfo
可以查看内存的信息 信息过长 此处不粘贴详细内容
cat/proc/meminfo 一般用 free -h代替
-h使free显示的内容可读
total一共 used 使用 free 剩余
[root@nfsnobody ~]# free -h 查看内存信息 -h参数 使free显示的内容可读
total used freeshared buffers cached
Mem:980M 619M 360M 228K 51M 397M
-/+ buffers/cache: 170M 809M
Swap:767M 0B 767M1.3 /proc/mounts
· Information system mounts
[root@nfsnobody ~]# cat /proc/mounts
用cat /proc/mounts 信息显示很杂乱 一般用column -t /proc/mounts代替
[root@nfsnobody ~]# column -t /proc/mounts ##使文件信息对齐后显示1.4 /proc/loadavg
System load information
core figure close to the total number of systems even higher
[root@nfsnobody~]# cat /proc/loadavg 显示系统负载信息
0.0 0.00 0.00 1/167 2280
最近一分钟 最近5分钟 最近15分钟 有167个进程 有一个在运行
[root@nfsnobody ~]# w 可用w代替 非全屏状态下可能会报错
23:30:33up 1:45,3 users, load average: 0.00,0.00, 0.00
USERTTY FROM LOGIN@ IDLEJCPU PCPU WHAT
roottty1 - 22:04 1:25m0.03s 0.03s -bash
rootpts/0 10.0.0.1 22:05 1:04m0.05s 0.05s -bash
rootpts/1 10.0.0.1 22:27 0.00s0.24s 0.13s w
[root@nfsnobody ~]# uptime 也能够查看系统负载
19:11:33 up 41 min,3 users, load average: 0.00,0.00, 0.00Chapter 2 / etc directory
2.1 /etc/sysconfig/network-scripts/ifcfg-eth0
2.1.1 Detailed information card
First NIC configuration file
system config/networ-scripts/interface(接口/w网卡)configIf you want to modify the information to modify the network card restart to take effect
[root@nfsnobody ~]# cat/etc/sysconfig/network-scripts/ifcfg-eth0 linux第一块网卡的配置文件
DEVICE=eth0 <==设备名称
TYPE=Ethernet <==网络类型以太网
UUID=9624a449-b94d-4633-9139-e8459206301d <==系统中给每个设备的标识符号在系统中唯一
ONBOOT=yes <==boot on 在开机或重启网络的时候自启动
NM_CONTROLLED=yes <==是否受系统的network服务控制
BOOTPROTO=none <==网卡获取IP的方法 网卡静态IP还是动态IP
HWADDR=00:0C:29:91:97:B5 <==HardWareADDRress硬件地址/MAC地址网卡唯一
IPADDR=10.0.0.201 <==服务器的ip地址
PREFIX=24
##等同于NATMASK=255.255.255.0 子网掩码 决定你一个局域网中最多可以有多少台服务器
GATEWAY=10.0.0.254 gate way 默认网关所有人离开进入都要经过网关
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"
DNS1=223.5.5.5 <== dns
DNS2=223.6.6.6 <== dns
BOOTPROTOstatic/none 静态IP
dhcp系统默认自动获取IP地址
NATMASK=255.255.255.0 这个一般没有 PREFIX=24 一般由这个代替
子网掩码 决定你一个局域网中最多可以有多少台服务器2.1.2 DNS
2.1.3 About DNS
DNS (domain name server / system) DNS
DNS (Public DNS) of the disposable
1. aliyun
DNS1 223.5.5.5
DNS2 223.6.6.6
2.114
114.114.114.114
114.114.115.1152.1.4 DNS increase in NIC
DEVICE=eth0 第一块网卡的配置文件/etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
UUID=4107073b-8277-471a-a2e7-a65cb8904475
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=none
HWADDR=00:0C:29:47:D6:37
IPADDR=10.0.0.200
PREFIX=24
GATEWAY=10.0.0.254
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"
DNS1=223.5.5.5###在底部加上 DNS
DNS2=223.6.6.6
在网卡配置文件/etc/sysconfig/network-scripts/ifcfg-eth0 加上DNS 然后重启网卡
/etc/init.d/network restart2.1.5 /etc/resolv.conf
DNS configuration file
card in the configuration file takes precedence over the /etc/resolv.conf
/etc/resolv.conf dns配置文件
[root@nfsnobody ~]# cat /etc/resolv.conf
# Generated by NetworkManager
# No nameservers found; try putting DNS serversinto your
# ifcfg files in /etc/sysconfig/network-scriptslike so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
nameserver 223.5.5.5
nameserver 223.6.6.62.2 /etc/sysconfig/network
Permanent (restart server) modify the host name of the place
[root@nfsnobody ~]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=nfsnobody2.3 /etc/sysconfig/network
2.3.1 temporarily modify the hostname
hostname
1.临时修改hostname
[root@nfsnobody ~]# hostname nfsnobody 修改
[root@nfsnobody ~]# hostname 查看
nfsnobody2.3.2 permanently modify the hostname
[root@nfsnobody ~]# vim /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=nfsnobody ##把名字修改为你要改的
修改完退出 重启服务器后生效2.4 /etc/hosts
ip domain name (hostname) analytical relationship
2.4.1 application scenarios
Set up a test environment
LAN DNS (understand)
2.4.2 understand the role of / etc / hosts of
[root@nfsnobody ~]# cat /etc/hosts 查看内容
127.0.0.1localhost localhost.localdomain localhost4 localhost4.localdomain4
::1localhost localhost.localdomain localhost6 localhost6.localdomain6
测试
[root@nfsnobody ~]# vim /etc/hosts
127.0.0.1localhost localhost.localdomain localhost4 localhost4.localdomain4
::1localhost localhost.localdomain localhost6 localhost6.localdomain6
10.0.0.200 jd.com ###IP地址与域名的对应关系
[root@nfsnobody ~]# ping jd.com 再次ping 京东 IP地址变为10.0.0.200
PING jd.com (10.0.0.200) 56(84) bytes of data.
64 bytes from jd.com (10.0.0.200): icmp_seq=1ttl=64 time=0.031 ms
64 bytes from jd.com (10.0.0.200): icmp_seq=2ttl=64 time=0.026 ms2.5 /etc/fstab
Created for each device at boot time an entry boot time automatically mount list
[root@nfsnobody ~]# column -t /etc/fstab 用 column -t 查看 可以先排列好内容再显示
#
#/etc/fstab
#Created by anaconda on Tue Jul 1018:21:44 2018
#
#Accessible filesystems, by reference, aremaintained under '/dev/disk'
#See man pages fstab(5), findfs(8),mount(8) and/or blkid(8)for more info
#
UUID=c4f4be67-f408-4f14-b01e-a0c0777932cb /ext4 defaults 1 1
UUID=8dc40910-35ed-4d1b-acd7-5dad0ad47746 /boot ext4 defaults 1 2
UUID=09e2ce6c-7249-4239-8843-5ef9cc3a9a99 swapswap defaults 0 0
tmpfs/dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 00
sysfs /sys sysfs defaults 0 0
proc/proc proc defaults 0 0
设备磁盘分区 挂载点
[root@nfsnobody ~]# blkid 可用blkid显示的信息与上面内容对比
/dev/sda1:UUID="8dc40910-35ed-4d1b-acd7-5dad0ad47746" TYPE="ext4"
/dev/sda2:UUID="09e2ce6c-7249-4239-8843-5ef9cc3a9a99" TYPE="swap"
/dev/sda3:UUID="c4f4be67-f408-4f14-b01e-a0c0777932cb" TYPE="ext4"2.6 /etc/rc.local
Storing boot from the start of the program or command to run automatically boot time
[root@nfsnobody ~]# cat /etc/rc.local
#!/bin/sh
#
# This script will be executed *after* all theother init scripts.
# You can put your own initialization stuff in hereif you don't
# want to do the full Sys V style init stuff.
##需要开机自启动的命令或脚本可以放在这个文件内
##效果类似于win7下面的启动2.7 /etc/inittab
2.7.1 Run-level profile
[root@nfsnobody ~]# cat /etc/inittab
# inittab is only used by upstart for the defaultrunlevel.
#
# ADDING OTHER CONFIGURATION HERE WILL HAVE NOEFFECT 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.confand /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), andinitctl(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 - Fullmultiuser mode
# 4 -unused
# 5 -X11
# 6 -reboot (Do NOT set initdefault to this)
#
id:3:initdefault: 需要更改直接vim在此处修改就可以2.7.2 Detailed operational level
# 0 - halt(Do NOT set initdefault to this) ##关机
# 1 -Single user mode ##单用户模式
# 2 -Multiuser, without NFS (The same as 3, if you do not have networking) ##多用户模式 没有NFS
# 3 - Fullmultiuser mode
##完全多用户模式 （命令行模式/文本模式）工作默认的环境
# 4 -unused 待开发
# 5 -X11 桌面模式图形化界面
# 6 -reboot (Do NOT set initdefault to this) #重启Chapter 3 Linux no Internet access
3.1 Troubleshooting Process
3.1.1 confirm whether access to the Internet
ping baidu.com3.1.2 DNS configuration issues
ping ip address (public IP)
223.5.5.5
114.114.114.1143.2 common cause
Resulting in no Internet access in common cause
1.IP address is correct
2. NIC configuration file is correct
gateway configuration errors
3.VMware virtual network card configuration
4. vmware8-Fi is turned on
5. Service is turned
6. If the modified under virtual gateway to modify restart machine