Linux下SSH免密码登录

搭建hadoop集群的时候一定会用到的就是SSH免密码登录

[hadoop@hadoop1 ~]$ ssh-keygen -t rsaGenerating public/private rsa key pair.Enter file in which to save the key (/home/hadoop/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/hadoop/.ssh/id_rsa.Your public key has been saved in /home/hadoop/.ssh/id_rsa.pub.The key fingerprint is:26:96:da:89:60:3d:90:75:43:bf:eb:56:d1:52:d9:68 hadoop@hadoop1The key's randomart image is:+--[ RSA 2048]----+|    ..+      +   ||   o . o    E .  ||  o     .  +     ||   o   . .o .    ||  o o + S  o     || . . * + ..      ||    o o ..       ||       ..        ||       ..        |+-----------------+[hadoop@hadoop1 ~]$ cd .ssh[hadoop@hadoop1 .ssh]$ scp -r id_rsa.pub hadoop@hadoop3:/home/hadoop/.ssh/authorized_keysThe authenticity of host 'hadoop3 (192.168.127.120)' can't be established.RSA key fingerprint is 03:be:af:08:19:27:6d:15:7e:dd:90:fa:09:b3:14:2f.Are you sure you want to continue connecting (yes/no)? yesWarning: Permanently added 'hadoop3,192.168.127.120' (RSA) to the list of known hosts.hadoop@hadoop3's password: id_rsa.pub                                                       100%  396     0.4KB/s   00:00    [hadoop@hadoop1 .ssh]$ ssh hadoop3Last login: Sat Aug  4 17:35:22 2012 from hadoop1

如果不能没有成功

方法一：

[hadoop@hadoop3 ~]$ chmod 700 .ssh/[hadoop@hadoop3 ~]$ cd .ssh[hadoop@hadoop3 .ssh]$ chmod 600 authorized_keys 

方法二：

[root@hadoop3 .ssh]# vi /etc/ssh/sshd_config AuthorizedKeysFile      .ssh/authorized_keys  把前面的#号去掉[root@hadoop3 .ssh]# /etc/rc.d/init.d/sshd restartStopping sshd:                                             [  OK  ]Starting sshd:                                             [  OK  ]