linux遇到的问题及解决方法

1. ssh remote host identification has changed [duplicate]
2. solve: ssh-keygen -R hostname
3. [ubuntu] ssh unrecognized service 
   
4. solve: sudo apt-get purge openssh-server, apt-get install openssl-server
5. [ubuntu] ssh connect to host port 22 connection refused 
6. solve: apt-get install openssl-server
   

7. Can not install openssh server

8. slove: 更改/etc/apt/source.list 的http://ro.archive.ubuntu.com/ubuntu/，使之是一个有效的server,如deb http://us.archive.ubuntu.com/ubuntu/

9. linux中好多软件以d结尾，d代表什么?一般是daemon，指后台进程的意思。大部分这种程序应该是服务类型的程序。

   
   
10. How to solve the time stamp is in the future error when you unpack a tar file on a system where the clock is behind the system clock on which you created the tar archive
    
    
    If you create a tar archive on system A and then try to unpack it on system B and system B's clock is behind that of system A then tar will complain.
    If you use the -m switch to tar then it will set all of the modified times on the unpacked files to the current system time.
    tar -xzmf archive.tar.gz
    
11. Fix arrow keys that display A B C D on remote shell
    

12. 1) Open Vim editor,2) Get the path of your home directory by typing :echo $HOME3) Check if you have .vimrc file in $HOME location,(if you don't have create it)4) Add the following line line to .vimrc file   set nocompatible        or     set nocp