Monday 24 October 2016

What is YUM (YellowDog Update Modifier) in centos ?


Yum (Yellowdog Update Modified) is RPM Packet Management system for Fedora, CentOS, Red Hat, OpenSuse etc. Yum history (list, info, summary, repeat, redo, undo, new) commands is added on 3.2.25 version. So this works every Linux Distros, which uses yum 3.2.25 or newer. Yum history command is a really useful in situations where the need to example rollback latest yum activity or undelete some deletes or just see what is updated lately.


11 Useful Yum Commands on CentOS Linux

Yum is the package management system that is used on CentOS Linux. It is responsible for managing packages and their dependencies from Yum repositories, as defined in /etc/yum.repos.d/
In this post, we’ll cover a few common and useful yum commands:

1. Install a yum package:

1yum install PACKAGE_NAME

2. Remove a yum package:

1yum remove PACKAGE_NAME

3. Reinstall a yum package:

1yum reinstall PACKAGE_NAME

4. Search for a yum package:

1yum search PACKAGE_NAME

5. Display the information of a yum package:

1yum info PACKAGE_NAME

6. Update installed yum packages:

1yum update

7. Update specific yum package:

1yum update PACKAGE_NAME

8. Show yum history:

1yum history

9. Show a list of enabled yum repositories:

1yum repolist

10. Find which yum package provides a particular file (eg: /usr/bin/nc):

1yum whatprovides "*bin/nc"

11. Clear yum cache:

1yum clean all

How To Reset Root Password On CentOS 7

Selection_005
3 – Go to the line of Linux 16 and change ro with rw init=/sysroot/bin/sh.

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4 – Now press Control+x to start on single user mode.
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5 – Now access the system with this command.
chroot /sysroot
6 – Reset the password.
passwd root
7 – Update selinux information
touch /.autorelabel
8 – Exit chroot
exit
9 – Reboot your system
reboot

Reference Link

Sunday 23 October 2016

An Open Letter to the HPC Community

We’re releasing PBS Professional under an open source license… why?
More than 20 years ago, I was just starting my career in HPC at NASA, where, along with a great team, we developed the original PBS software. Today, PBS Professional is among the most-used technologies for HPC job scheduling. But scheduling is hard — every site has unique processes, unique goals, and unique business requirements. In fact, there are at least a dozen different software packages that are in use across the globe for HPC job scheduling, in traditional HPC centers and in both private and public clouds. A dozen? Why?
Looking back over the last couple of decades, I believe a big reason is that the HPC world is really two worlds:
  • The public sector – researchers and scientists from universities and national labs are breaking new ground and pushing the limits of HPC – natural collaborators, early adopters and risk takers, which leads to a strong preference for open source software, and
  • The private sector – engineers and businesspeople from corporations are building products and delivering services leveraging HPC as a tool for competitive advantage – natural competitors, later adopters and risk-averse, which leads to a strong preference, often a requirement, for commercial software.
Because the community is split, innovations do not easily flow from one sector to the other, and rather than advancing the state of the art, efforts are wasted re-implementing the same old capabilities again and again. This is a HUGE missed opportunity.
Altair is making a big investment toward uniting the whole HPC community to accelerate the state of the art (and the state of actual production operations) for HPC scheduling. We are dual-licensing PBS Professional®, both open source and commercial. We are opening the full core of the software, not just a weak subset or older version. We are continuing to offer a hardened, commercial version for commercial customers. We are committing to being aggressively open and community oriented. We are adding staff and reorganizing our engineering organization to behave as one of (hopefully) many contributors to the project. We are using community-accepted best practices (e.g., Github, JIRA, open discussions for new features). We are joining the OpenHPC project with PBS Pro. And, we are focused on longevity – creating a viable, sustainable community to focus on job scheduling software that can truly bridge the gap in the HPC world.
Excited? Honestly, this is one of the most exciting activities I’ve been involved in since bringing PBS Pro out of NASA in the first place. Getting the software in shape for release has required a lot of effort. We are on track for releasing open source PBS Pro 14.0 in mid-2016. It’s not only opening the source code, but also creating the tools and processes for nurturing a community – documentation, ticketing system, continuous integration tools, wikis, email lists, etc. We want to “do it right”. Of course, once we go live, I’m sure we’ll learn a great deal (from people like you), and we will work hard to best support the needs of the community.
Obviously, we cannot do this alone!
We want your input, your help; please join us as part of the PBS Pro community.
(This post originally appeared on InsideHPC on 3 May 2016.)

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