linux常見故障處理

一. 文件和目錄類

1.1 File exist 文件已經存在

[root@oldboyedu59 ~]# mkdir   /data   /lidao  
[root@oldboyedu59 ~]# mkdir   /data   /lidao  
mkdir: cannot create directory ‘/data’: File exists
mkdir: cannot create directory ‘/lidao’: File exists

mkdir: cannot create directory ‘/lidao’: File exists
沒法 建立 目錄 由於這個目錄已經存在

1.2 No such file or directory 沒有這個文件或目錄（這個東西不存在）

沒有這個目錄:文件或路徑書寫錯誤

[root@oldboyedu59 ~]# mkdir  /oldboy
[root@oldboyedu59 ~]# cd oldboy
-bash: cd: oldboy: No such file or directory

mkdir命令自己問題:mkdir 命令默認只能建立1層目錄 建立多層報錯
-p解決

[root@oldboyedu59 ~]# mkdir  /data/oldboy/lidao/
mkdir: cannot create directory ‘/data/oldboy/lidao/’: No such file or directory

touch命令只能建立文件,目錄不存在則會報錯
解決:先建立目錄,再建立文件

[root@oldboyedu59 ~]# ls /oldboy/
oldboy.txt
[root@oldboyedu59 ~]# touch /oldboy/lidao/alex/oldboy.txt
touch: cannot touch ‘/oldboy/lidao/alex/oldboy.txt’: No such file or directory

排錯思路：

一、ls命令檢查對應的目錄是否存在?

二、目錄不存在 先建立目錄在建立文件/

1.3 command not found 命令找不到（沒有這個命令）

[root@oldboyedu59 ~]# mkdiy
-bash: mkdiy: command not found

1.書寫錯誤
2.沒有安裝

1.4 invalid option 無效的參數（不可用的參數）

[root@oldboyedu59 ~]# touch -p /oldboy/oldboy.txt
touch: invalid option -- 'p'
Try 'touch --help' for more information.

1.5 overwrite 覆蓋

cp複製若是已經存在這個文件會提示是否覆蓋

[root@oldboyedu59 ~]# cp  /oldboy/oldboy.txt   /tmp/
cp: overwrite ‘/tmp/oldboy.txt’?

1.6 remove regular empty file 是否刪除普通文件（空的）

[root@oldboyedu59 ~]# rm   /oldboy/oldboy.txt
rm: remove regular empty file ‘/oldboy/oldboy.txt’?

1.7 is a directory xxx是一個目錄

rm默認沒法刪除目錄
解決:加上-r 或-rf

[root@oldboyedu59 ~]# rm /data/
rm: cannot remove ‘/data/’: Is a directory

vi命令中 使用vi編輯目錄也會報錯

"/oldboy"
E502: "/oldboy" is a directory
Press ENTER or type command to continue

1.8 descend into directory 是否進入目錄

[root@oldboyedu59 ~]# rm -r /data/
rm: descend into directory ‘/data/’? y
rm: remove regular empty file ‘/data/oldboy01.txt’? n
rm: remove regular empty file ‘/data/oldboy02.txt’? n
rm: remove regular empty file ‘/data/oldboy03.txt’? n
rm: remove regular empty file ‘/data/oldboy04.txt’? n
rm: remove regular empty file ‘/data/oldboy05.txt’? n
rm: remove regular empty file ‘/data/oldboy06.txt’? n
rm: remove regular empty file ‘/data/oldboy07.txt’? n
rm: remove regular empty file ‘/data/oldboy08.txt’? n
rm: remove regular empty file ‘/data/oldboy09.txt’? n
rm: remove regular empty file ‘/data/oldboy10.txt’? n
rm: remove directory ‘/data/’? n
1.9 Invalid level 無效的層數,層數必須大於0

注意參數位置

[root@oldboyedu59 ~]# tree  -L -F 2 / 
tree: Invalid level, must be greater than 0.

1.10 Can't open file for writing 沒法打開這個文件

vi中 若是目錄不存在就會提示

"/oldbyo/oldboy.txt"
"/oldbyo/oldboy.txt" E212: Can't open file for writing
Press ENTER or type command to continue

1.11 No write since last change

E37: No write since last change (add ! to override)
     粘包賴(你修改了內容就沒法使用:q退出 須要使用:q!

1.12 xx column window is too narrow 窗口只有xx列太窄了 沒法徹底顯示

這是w的坑 空間過小施展不開.

[root@oldboyedu60-lnb ~]# w
w: 39 column window is too narrow

二. 網絡鏈接類

2.1 遠程鏈接錯誤 Connection Failed 鏈接失敗

使用Xshell遠程鏈接失敗提示,檢查端口是否開啓或正確

[c:\~]$ 

Connecting to 10.0.0.200:233...
Could not connect to '10.0.0.200' (port 233): Connection failed.

Type `help' to learn how to use Xshell prompt.

使用telnet測試端口是否打開

[c:\~]$ telnet 10.0.0.200 233 

Connecting to 10.0.0.200:233...
Could not connect to '10.0.0.200' (port 233): Connection failed.   #233端口沒有開啓

Type `help' to learn how to use Xshell prompt.

端口開啓

[c:\~]$ telnet 10.0.0.200 22
Connecting to 10.0.0.200:22...
Connection established.            #端口開啓
To escape to local shell, press 'Ctrl+Alt+]'.
SSH-2.0-OpenSSH_7.4

Protocol mismatch.

Connection closed by foreign host.

Disconnected from remote host(10.0.0.200:22) at 12:22:54.

Type `help' to learn how to use Xshell prompt.
[c:\~]$

2.2 yum安裝軟件故障提示 Could not resolve host沒法解析主機

Could not resolve host沒法解析主機
主要是系統可否上網和DNS問題.

http://mirrors.tuna.tsinghua.edu.cn/centos/7.6.1810/updates/x86_64/repodata/repomd.xml: [Errno 14] curl#6 - 
"Could not resolve host: mirrors.tuna.tsinghua.edu.cn; Unknown error"
Trying other mirror.

2.3 yum安裝軟件提示:Nothing to do (沒事作)

有兩種狀況:
狀況1:軟件已經安裝而且最新以下:

Package tree-1.6.0-10.el7.x86_64 already installed and latest version
tree軟件包已經安裝而且是最新版本
Package 2:vim-enhanced-7.4.160-5.el7.x86_64 already installed and latest version
Package 1:bash-completion-2.1-6.el7.noarch already installed and latest version
Nothing to do

狀況2:軟件名字寫錯或沒有配置yum源致使找不到這個軟件包

[root@oldboyedu60-lnb ~]# yum install treea -y
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirror.lzu.edu.cn
 * extras: mirrors.nwsuaf.edu.cn
 * updates: mirrors.nwsuaf.edu.cn
base                                                                                              | 3.6 kB  00:00:00     
extras                                                                                            | 3.4 kB  00:00:00     
updates                                                                                           | 3.4 kB  00:00:00     
No package treea available. 
#沒有找到叫treea的軟件包
Error: Nothing to do

2.4 Name or service not known 域名沒法識別（沒法上網）

緣由：

1：DNS配置錯誤緣由

2：Linux沒法上網緣由

[root@oldboyedu59 ~]# ping baidu.com 
ping: baidu.com: Name or service not known
  域名沒法識別（沒法將域名---->ip地址)

三. 修改系統基礎配置類

3.1 重啓網卡報錯 device not present

[root@oldboyusd ~]# systemctl restart network 
Job for network.service failed because the control process exited with error code.
 See "systemctl status network.service" and "journalctl -xe" for details.

查看詳細錯誤緣由
·journalctl -xe·

Apr 01 15:31:05 oldboyusd.1 network[7816]: Bringing up interface etho:  ERROR     : [/etc/sysconfig/network-scripts/ifup-eth] Device  does not seem to be present, delaying initialization.

Apr 01 15:31:05 oldboyusd.1 /etc/sysconfig/network-scripts/ifup-eth[8019]: Device  does not seem to be present, delaying initializatio

3.2 修改主機名過程當中,命令行中主機名沒有變化

1 hostname命令修改主機名（臨時 重啓服務器以後失效）

[root@oldboyedu59 ~]# hostname
oldboyedu59
[root@oldboyedu59 ~]# hostname oldboyedu59-lnb

2 修改文件內容（寫合同 永久 重啓服務器以後生效）

vim /etc/hostname 
 oldboyedu59-lnb

3 檢查

[root@oldboyedu59 ~]# hostname
oldboyedu59-lnb
[root@oldboyedu59 ~]# cat /etc/hostname 
oldboyedu59-lnb

命令行中的主機名部分沒有改變？

解決：從新登陸下便可（斷開鏈接，從新鏈接）

[root@oldboyedu59-lnb ~]#