"Hadoop series" Linux root user password-free login to remote host SSH

Operating Environment: CentOS 6.5

Action object: User A host and remote Host B

Body part: Italic bold represents Linux instructions.

Linux non-root user password-free login remote host SSH Please go to this link: xxxxxxxxxxxxxxxx (not yet written) One, remote Host B and user A are installed OpenSSH

First we check whether the remote host installs OPENSHH and rsync

Rpm-qa|grep OpenSSH
Rpm-qa|grep rsync

If no information is returned and the representative is not installed, we install it with the Yum command.

Yum Install Openssh-y

Yum Install Openssh-server-y

Yum Install Openssh-clients-y

Yum Install Rsync-y

(Delete openshh and rsync

Yum Remove openssh-y

Yum Remove rsync-y)

second, the user a host generates the public and private keys.

ssh-keygen-t rsa-p ' (' Default path ')

When prompted, enter to install the public and private keys in the default path. /root/.ssh/id_rsa and/root/.ssh/id_rsa.pub

third, remote Host B creates the/root/.ssh folder.

The remote host holds the path to the public and private keys in the/root/.ssh/authorized_keys file.

Because the remote host did not pass the second step, there is no/root/.ssh this folder.

The/root/.ssh folder can be obtained from the two different methods of creating a file with Linux instructions or generating a public and private key on a remote host .

⑴ through the Linux directive (this needs to consider the permissions of the folder, otherwise the user a host cannot log on to remote Host B without a password),

Here's how:

On remote Host B

⑵ performs the second step to obtain the public and private keys while obtaining the/root/.ssh folder (the benefit of doing so without considering the permissions of the folder),

Here's how:

ssh-keygen-t rsa-p ' (' Default path ')

When prompted, enter to install the public and private keys in the default path. /root/.ssh/id_rsa and/root/.ssh/id_rsa.pub

Four, the user a host's public key is still on the remote Host B.

In the third step, we obtained the/ROOT/.SSH folder on the remote Host B, and now we place the public key of the user a host under the folder, and then append it to the/root/.ssh/authorized_keys file.

/root/.ssh/authorized_keys files may not be available beforehand.

Here's how:

⑴ still public key:SCP ~/.ssh/id_rsa.pub [email protected]:~/.ssh(User a host operation)

⑵ Append to File: Cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys (remote Server B host operation)

⑶ Modify the contents of the/etc/ssh/sshd_config:

Vi/etc/ssh/sshd_config

(#RSAAuthentication Yes
#PubkeyAuthentication Yes
#AuthorizedKeysFile. Ssh/authorized_keys

Find the above 3 statements and take the previous # number off)

Note: Some articles say to/root/.ssh this folder and/root/.ssh/authorized_keys this file, you have to modify the permissions.

However, in my operation under root, if you change the/root/.ssh/authorized_keys file permissions to 600 will not be able to use password-free login, it is best to not change permissions under root.

Five, User a host password-free logon remote server B.

SSH 192.168.31.230

You can login without a password. (Exit exit)

At this point we also completed the Linux root user password-free login to the remote server.

"Hadoop series" Linux root user password-free login to remote host SSH