指令下達

1. 格式
   

   [root@deyu dywang]#	command	[ -options ]	parameter1	parameter2	...
   	指令	選項	參數1	參數2

   1. Linux 環境下，大小寫不同;
   2. 選項可不指定， [ ] 並不存在於實際的指令中，通常以 "-" 加入選項設定，有時完整參數名稱以 "--" 輸入;
   3. 指令、選項及參數間以空格區分(個數不拘);
   4. 按下 [Enter]，開始執行指令。
   5. 指令太長可以跳脫字元 "\" ，跳脫 [Enter]動作，換行繼續輸入。
2. 切換至root身份
   

   [dywang@deyu ~]$ su -
   [root@deyu ~]#
   

3. 以ssh連線至虛擬機
   

   [root@deyu ~]# ssh root@kvm4.deyu.wang
   The authenticity of host 'kvm4.deyu.wang (192.168.122.4)' can't be established.
   RSA key fingerprint is f2:04:37:1e:5b:7c:86:0d:c6:c6:3e:6b:85:a7:5d:6f.
   Are you sure you want to continue connecting (yes/no)? yes
   Warning: Permanently added 'kvm4.deyu.wang' (RSA) to the list of known hosts.
   root@kvm4.deyu.wang's password: 
   Last login: Tue Dec 20 09:00:03 2011
   [root@kvm4 ~]# w
    09:10:19 up 32 min,  1 user,  load average: 0.00, 0.00, 0.00
   USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
   root     pts/0    deyu.wang        09:09    0.00s  0.04s  0.01s w
   [root@kvm4 ~]# ls
   anaconda-ks.cfg  install.log  install.log.syslog
   [root@kvm4 ~]# exit
   logout
   Connection to kvm4.deyu.wang closed.
   [root@deyu ~]# cat ~/.ssh/known_hosts
   kvm4.deyu.wang ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAlUrRxmSY4ngrTFj1dpW9XzHdgzNxl2Dt3rwpMui8UlieYiedHMKzqMoBjN72OzBxPbT/E1aYUlwZeY60kbvQMcZ3RZYrT3zhnhVAzQPJ4RfqBEBG3xVdH2amz630KKOnPn5tBFG3EnHu3ot+bL/ArNTFDIKfUkuY9LBASgjCxIw/lUlVUZNcpo+3EpBryzWZ7DzNahgctQ0CU10FXJDqxLKM9VSzugrUMhf+tjb3OTyf8PM+g8DDFFifWinNa9qoBf6s5fZajj/xANhTw2OYgn/jETSXtTOZVZ3K7vcABwdnfwNkBnGnxn9jo1ND5QzITqRmBGWDa1M6W5pnp+xPUQ==
   [root@deyu ~]# ssh root@kvm4.deyu.wang
   root@kvm4.deyu.wang's password: 
   Last login: Tue Dec 20 09:09:55 2011 from deyu.wang
   [root@kvm4 ~]# exit
   logout
   Connection to kvm4.deyu.wang closed.
   [root@deyu ~]# rm ~/.ssh/known_hosts
   [root@deyu ~]# ssh root@kvm4.deyu.wang
   root@kvm4.deyu.wang's password: 
   Last login: Sun Jan  1 16:41:28 2012 from 192.168.122.1
   [root@kvm4 ~]#