How to Setup the Intel Compilers on a Cluster

Intel compilers like icc or icl are very useful for any cluster with Intel processors. They’ve been known to produce very efficient numerical code. If you are still a student, you can grab the student Intel Parallel Studio XE Cluster Edition, which includes Fortran and C/C++ for free for a...

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Running MPI – Common MPI Troubleshooting Problems

In this post, I’ll list some common troubleshooting problems that I have experienced with MPI libraries after I compiled MPICH on my cluster for the first time. The following assumes that: You have at least 2 nodes as part of your cluster. You have MPI compiled inside a NFS (Network...

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yum [Errno 14] HTTP Error 404 – Not Found

When you run a yum command like: yum install vim You may get the following error: Loaded plugins: fastestmirror http://repo.dimenoc.com/pub/centos/7.1.1503/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 – Not Found Trying other mirror. Is this ok [y/d/N]: y Downloading packages: Delta RPMs disabled because /usr/bin/applydeltarpm not installed. vim-enhanced-7.4.160-1.el7.x86 FAILED http://ftp.linux.ncsu.edu/pub/CentOS/7.1.1503/os/x86_64/Packages/vim-enhanced-7.4.160-1.el7.x86_64.rpm: [Errno 14]...

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Easy Malware Removal Guide

You might be using your computer one day and notice that there’s some weird behavior occurring. Maybe, it’s the random popups or system crashes, strange warnings or dialog messages, excessive network activity, and programs start misbehaving (randomly opening, crashing, or strange error messages), you might be infected with malware. Here...

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How to Fix yum Could not resolve host: repo Unknown error

You may receive a problem with yum not being able to resolve hosts when you try to install a yum package. I’m using CentOS 7. yum install wget

If you already have Internet connection and can ping 8.8.8.8, the likely problem is that you don’t have nameservers in your...

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How to Change hostname on CentOS 7

The best way to change hostname on CentOS 7 is editing the actual file that controls the hostname. vi /etc/hostname Originally, it is: localhost.localdomain But, we’ll delete that line and change it to: buhpc2 buhpc is our hostname, but it also has the subdomain, 2.buhpc.com, that I have configured. Now,...

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How to Create SSH Keys for Secure SSH Access

Create SSH keys for SSHing SSH keys allow you to SSH into a machine without a password prompt. Before we create our SSH key, make sure that we have a ~/.ssh folder. If not, create the ~/.ssh folder. mkdir ~/.ssh Now, we can use the following command to generate an SSH...

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How to Setup Shortcuts for SSH

Instead of using SSH on an IP address that you’ll definitely forget, you can use shortcuts instead! For instance, instead of typing: ssh username@192.168.1.1 Wouldn’t you rather do something like:

  Creating SSH shortcuts To create shortcuts, you have to create a file inside your home directory’s .ssh folder...

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How to Set Static IP Address on CentOS 7

This blog post will show you how to set a static IP address on CentOS 7 from scratch with no prior knowledge of any information about the network. See if NetworkManager is running. NetworkManager is a network daemon that handles our network interfaces dynamically, but we’ll change our network scripts to...

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