Category: CentOS 7

Setup Hostname without DNS Server on CentOS 7

Let’s say that you have a cluster of 6 nodes and you do not have a DNS server. How do you map the IPs to their perspective hostnames properly so that every node in the cluster can detect the other node’s hostname? We need to bypass the automatic lookup. I have 6 nodes with the following IPs and hostnames. 128.197.115.158 buhpc1 128.197.115.7 buhpc2 128.197.115.176 buhpc3 128.197.115.17 buhpc4 128.197.115.9 buhpc5 128.197.115.15 buhpc6 Now, we edit every node’s /etc/hosts file. For all...

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How to Mount USB Flash Drive on CentOS 7

In this blog article, I’ll show you how to mount a USB Flash Drive on CentOS 7 terminal. In my case, I needed to mount a USB Flash Drive on my minimal CentOS 7 machine to copy a file to the USB Flash Drive. USB Flash Drive The file system of my USB flash drive is FAT32. I used a Windows 10 computer to create a folder called System Volume Information on the USB flash drive. Mounting First, go to your...

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How to Run HPL (LINPACK) Across Nodes – Guide

We’ve been working on a benchmark called HPL also known as High Performance LINPACK on our cluster. Our cluster is made of 6 nodes. The specs are: 6 x86 nodes each with an Intel(R) Xeon (R) CPU 5140 @ 2.33 GHz, 4 cores, and no accelerators. Our OS is CentOS 7. At first, we had difficulty improving HPL performance across nodes. For some reason, we would get the same performance with 1 node compared to 6 nodes. Here’s what we...

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How to Install Ansible on CentOS 7

Ansible is a useful configuration automation software that allows you to automate the setup of your machines. In comparison to other configuration automation out there like Chef or Puppet, I’ve found it to be much simpler to use for cluster setup. Installation First, I normally update the EPEL on CentOS 7 before installing ansible. yum install epel-release Afterwards, we can use yum install to setup ansible on our machine. If you have a cluster, install ansible on each individual node....

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How to Install Slurm on CentOS 7 Cluster

Slurm is an open-source workload manager designed for Linux clusters of all sizes. It’s a great system for queuing jobs for your HPC applications. I’m going to show you how to install Slurm on a CentOS 7 cluster. Delete failed installation of Slurm Install MariaDB Create the global users Install  Munge Install Slurm Use Slurm Cluster Server and Compute Nodes I configured our nodes with the following hostnames using these steps. Our server is: buhpc3 The clients are: buhpc1 buhpc2...

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How to Install GlusterFS on CentOS 7

GlusterFS is a scale-out network-attached storage file system. In this tutorial, we’ll be setting up GlusterFS on a cluster with CentOS 7.  Our cluster has 6 nodes connected through a switch. I’ll be using all 6 nodes as servers for distributed replicated storage with opportunity for more nodes to be clients that can access files from the GlusterFS servers. How does GlusterFS work In a GlusterFS, servers are used to store data in a distributed manner, and clients can access...

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How to Install Ganglia on CentOS 7

Ganglia is a scalable distributed monitoring system for high-performance computing systems such as clusters and Grids. Ganglia is useful when monitoring nodes of a cluster. Setting up Ganglia on CentOS 7 with a bunch of nodes can be confusing. In this blog, I’ll show you how to setup Ganglia and its web interface properly. Our cluster has 6 nodes connected through a switch. Cluster Server and Clients I configured our nodes with the following hostnames using these steps. Our server...

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How to Bypass Intel PXE Boot

You might encounter a PXE Boot loading screen on your cluster, but you don’t have PXE Boot. And your network isn’t even configured yet! Many machines built to be part of clusters will pop up to this PXE screen and will loop forever! What do you do?   Change the Boot Order Let’s say that all I want to do is boot the machine and install a new operating system. I have my trusty CentOS 7 Bootable USB installer drive...

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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 year. Here’s our experience. If you need more information, definitely check out the official Intel Parallel Studio XE Cluster Edition guide. Dependencies You should have the GCC C and C++...

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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] HTTP Error 404 – Not Found To fix the error: yum clean all yum update Now try again: yum install vim The command should continue normally.

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