Configuring SSH to use Protocol 2 or SSHv2 in CentOS

To disable SSHv1 or SSH Protocol 1, do the following:

Check for Protocol configuration

# cat /etc/ssh/sshd_config |grep Protocol

Ensure that you should get only Protocol 2

Protocol 2

If not, Edit the /etc/ssh/sshd_config to reflect only Protocol 2

# vim /etc/ssh/sshd_config

Search for the word Protocol and make the necessary changes.

Restart OpeenSSH Server

# service sshd restart

Unable to clear the offline mode for Compute node using pbsnodes command

If you try to make a node online after you deliberately off-line the node perhaps for some repair work and unable to online again. Instead on your Torque Server,  you see errors such as these

PBS_Server: LOG_ERROR::is_request, bad attempt to connect from
192.168.1.1:1023 (address not trusted - check entry in server_priv/nodes

As the log says, there is some issue in the server_priv configuration. If all your nodes are working well except that, you should take a look at the client settings. Maybe your server_priv has the wrong configration.

Once you have cleared the error, just fire off the command

# pbsnodes -c node_name

Donate unused Computer Cycles to World Community Grid

You can join the World Community Grid (WCG) and donate your unused computer cycles and support innovative humanitarian research being conducted all over the world. WCG is a community of over 600,000 people and 1.4 million machines and is the world's largest, free, volunteer super-computer dedicated solely to addressing global medical and scientific issues.

Free Technical Resources at IBM Student Portal

No-charge technical resources are available for students at IBM Student Portal. You can access software downloads and eBooks to learn about leading technologies.

Installing lapack, blas and atlas on CentOS 5

Installing lapack, blas and atlas on CentOS 5.4 is very simple.Firstly you must enable the follow repositories:

1. atlas package - EPEL (For more information on how to download EPEL, see Red Hat Enterprise Linux / CentOS Linux Enable EPEL Repository
2. blas and lapack packages - RPMForge (For more information on how to download RPMForge, See Install RPMForge

Installing atlas, blas and lapack x86_64 packages

# yum install atlas.x86_64 blas.x86_64 lapack.x86_64