Linux Blimp

In previous articles, I examined some fundamental tools for HPC systems, including pdsh (parallel shells), Lmod environment modules, and shared storage with NFS and SSHFS. One remaining, virtually indispensable tool is a job scheduler.

One of the most critical pieces of software on a shared cluster is the resource manager, commonly called a job scheduler, which allows users to share the system in a very efficient and cost-effective way. The idea is fairly simple: Users write small scripts, commonly called “jobs,” that define what they want to run and the required resources, which they then submit to the resource manager. When the resources are available, the resource manager executes the job script on behalf of the user. Typically this approach is for batch jobs (i.e., jobs that are not interactive), but it can also be used for interactive jobs, for which the resource manager gives you a shell prompt to the node that is running your job.

Some resource managers are commercially supported and some are open source, either with or without a support option. The list of candidates is fairly long, but the one I talk about in this article is Slurm. …The SLUM architecture is very similar to other job schedulers. Each node in the cluster has a daemon running, which in this case is named slurmd. The resources are referred to as nodes. The daemons can communicate in a hierarchical fashion that accommodates fault tolerance. On the Slurm master node, the daemon is slurmctld, which also has failover capability.

Read more at ADMIN magazine

Source

Nextcloud is an open source, self-hosted file share and collaboration platform, similar to Dropbox. It comes bundled with media player, calendar and contact management.

Nextcloud is extensible via apps and has desktop and mobile clients for all major platforms.

This tutorial will walk you through the process of installing and configuring Nextcloud with Apache on a CentOS 7 system.

Prerequisites

Before starting with the tutorial, make sure you are logged in as a user with sudo privileges.

Step 1: Creating MySQL Database

NextCloud can use SQLite, PostgreSQL or MySQL database to store all its data.

In this tutorial we will use MySQL as the database of choice.

If you already don’t have MySQL or MariaDB installed on your CentOS server you can install by following one of the instructions below:

• Install MySQL on CentOS 7
• Install MariaDB on CentOS 7

Start by logging to to the MySQL shell by typing the following command:

Run the following SQL statements to create a database named nextcloud, user named nextclouduser and to grant the necessary privileges to the user:

CREATE DATABASE nextcloud CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;
GRANT ALL ON nextcloud.* TO ‘nextclouduser’@’localhost’ IDENTIFIED BY ‘change-with-strong-password’;
FLUSH PRIVILEGES;
EXIT;

Step 2: Installing PHP and Apache

Nextcloud is a PHP application. CentOS 7 ships with PHP 5.4 which is not supported by Nextcloud.

We will install PHP 7.1 from the Remi repository. The commands below will enable EPEL and Remi repositories:

sudo yum install epel-release yum-utils
sudo yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm
sudo yum-config-manager –enable remi-php71

Once the repositories are enabled install Apache PHP 7.1 and all required PHP extensions with the following command:

sudo yum install httpd php php-gd php-json php-mysql php-curl php-mbstring php-intl php-mcrypt php-imagick php-xml php-zip

Step 3: Configuring firewall

If you are running Firewall on your CentOS server, you’ll need to open HTTP (80) and HTTPS (443) ports.

You can do that by running the following commands:

sudo firewall-cmd –permanent –zone=public –add-service=http
sudo firewall-cmd –permanent –zone=public –add-service=https
sudo firewall-cmd –reload

Step 4: Downloading Nextcloud

Download the latest version of Nextcloud from the Nextcloud download page with wget:

wget -P /tmp https://download.nextcloud.com/server/releases/nextcloud-14.0.3.zip

At the time of writing this article, the latest version of Nextcloud is version 14.0.3.

Once the download is complete, extract the archive and move the Nextcloud extracted files to the /var/www directory:

unzip /tmp/nextcloud-14.0.3.zip
sudo mv /tmp/nextcloud /var/www/

Set the correct permissions so that the Apache web server can have full access to the Nextcloud’s files and directories.

sudo chown -R apache: /var/www/nextcloud

Step 5: Configure Apache

Open your text editor and create the following Apache configuration file.

sudo nano /etc/httpd/conf.d/nextcloud.conf

/etc/httpd/conf.d/nextcloud.conf

Alias /nextcloud “/var/www/nextcloud/”

<Directory /var/www/nextcloud/>
Options +FollowSymlinks
AllowOverride All

<IfModule mod_dav.c>
Dav off
</IfModule>

SetEnv HOME /var/www/nextcloud
SetEnv HTTP_HOME /var/www/nextcloud

</Directory>

Activate the changes by restarting Apache service:

sudo systemctl restart httpd

Step 6: Installing Nextcloud

Now that Nextcloud is downloaded and all necessary services are configured open you browser and start the Nextcloud installation by visiting your server’s domain name or IP address followed by /nextcloud :

http://domain_name_or_ip_address/nextcloud

You will be presented with the Nextcloud setup page.

Enter your desired admin username and password and the MySQL user and database details you previously created.

Click on the Finish setup button and once the installation process is completed you will be redirected to the Nextcloud dashboard logged in as admin user.

Conclusion

You have learned how to install and configure Nextcloud on your CentOS 7 machine. If you have a domain name associated with your Nextcloud server, you can follow this guide and secure your Apache with Let’s Encrypt.

To find more information about how to manage your Nextcloud instance visit the Nextcloud documentation page.

If you have any question, please leave a comment below.

Source

For those curious about the performance of IBM’s POWER9 processors against the likes of today’s AMD Threadripper and Intel Core i9 HEDT processors, here are some interesting benchmarks as we begin looking closer at the POWER9 performance on the fully open-source Raptor Talos II Secure Workstation. This open-source, secure system arrived for Linux testing with dual 22-core POWER9 CPUs to yield 176 total threads of power.

 

 

As mentioned a few days ago in the aforelinked article, Raptor Computing Systems recent sent over a Talos II system for benchmarking to deliver more frequent benchmarks from this high-end workstation/server that’s fully open-source down to the motherboard firmware and BMC stack. We previously have carried out some remote benchmarks of the Talos II, but now having it in our labs allows us to more frequently conduct tests as well as swapping out the hardware, matching other test systems, and also other tests like performance-per-Watt comparisons that were not possible with the remote testing.

 

 

Besides being fully open-source, the Talos II is also manufactured in the US with the IBM POWER9 processors being fabbed in New York while the Raptor motherboard is manufactured in Texas along with where their systems are assembled. The Talos II motherboard features five PCI Express 4.0 slots for next-gen connectivity, dual Gigabit Ethernet, and can accommodate two POWER9 “Sforza” CPUs that support four memory channels per socket.

 

 

The POWER9 Sforza-based Talos II was being compared to AMD Threadripper and Intel Core i9 for this initial article given these CPUs all supporting four DDR4 memory channels. Some Talos II comparisons to AMD EPYC and Intel Xeon hardware will be coming up soon on Phoronix for reference. It’s the larger LaGrange/Monza POWER9 modules that support eight memory channels that are more akin to the Xeon/EPYC competition.

 

 

As for the attention to detail with Talos II being an open-source product, included with the system is a DVD containing the system schematics as well as the firmware source code. That DVD copy is the exact source used to build the pre-loaded firmware though also available via git.raptorcs.com is all of the platform firmware code, CPU firmware, BMC firmware, host firmware, OpenBMC code, and OpenPOWER bits.

 

 

Pricing on POWER hardware remains a bit high depending upon your budget: pricing on the motherboard itself is $2,499.00 or $1,129.99 for the Lite version that is single-socket only. Pricing on the IBM POWER9 CPUs starts at $375 USD for the quad-core or $2625 USD for the 22-core processor. Pricing is certainly higher than Threadripper / Core i9 but the system is fully open-source and audit-able for security and in the case of this dual 22-core setup offers 176 threads thanks to 4-way SMT.

 

 

For those looking to find a high-performance POWER9 libre system on a budget, Raptor Computing Systems has been working on Blackbird with more information on that lower-cost board due out soon.
Source

Source

This is in fact the Fedora GNOME Live distribution, but because GNOME is the default desktop environment of the Fedora Linux operating system, it is simply called Fedora Live CD. It is also the only Live CD edition of Fedora to feature a custom welcome screen that lets users to choose between the live mode or the install mode.

Availability, boot options, supported platforms

Just like any other Fedora Live CD flavor, this edition is distributed as Live DVD ISO images engineered to support both 64-bit (x86_64) and 32-bit (x86) instruction set architectures. They can be burned onto DVD discs or written on USB thumb drives of 1GB or higher capacity.

From the boot prompt, users can start the live environment with default settings or in safe graphics mode, boot an existing operating system from the first disk drive, run system memory test, or check the disc for defects (only if using a DVD media).

Pure GNOME experience with a default set of apps

The graphical session of this Fedora Live CD is powered by the modern GNOME desktop environment, which includes most of the standard GNOME apps. The desktop features a single top panel from where users can open apps, interact with running programs, as well as to switch between virtual workspaces.

Default applications include the LibreOffice office suite, Mozilla Firefox web browser, Cheese webcam viewer, Empathy instant messenger, Evolution email and calendar client, Gedit text editor, Shotwell image viewer and organizer, Totem video player, as well as Rhythmbox music player.

As mentioned, some of the default GNOME apps are also included in this Fedora edition, such as Clocks, Documents, Contacts, Files, Software, Terminal, Font Viewer, Screenshot, Calculator, Character Map, Disks, Disk Usage Analyzer, Document Viewer, System Monitor, Remote Desktop Client, and Orca.

Bottom line

Summing up, Fedora Live CD is a freely distributed and open source operating system that allows users to test the latest features of the Fedora Linux distribution without installing anything on their computers.

Source

Blockchain and its ability to “embed trust” can help elevate trust, which right now, is low, according to Sally Eaves, a chief technology officer and strategic advisor to the Forbes Technology Council, speaking at The Linux Foundation’s Open FinTech Forum in New York City.

People’s trust in business, media, government and non-government organizations (NGOs) is at a 17-year low, and businesses are suffering as a result, Eaves said.

Additionally, Eaves said, 87 percent of millennials believe business success should be measured in more than just financial performance. People want jobs with real meaning and purpose, she added.

To provide further context, Eaves noted the following urgent global challenges:

• 1.5 billion people cannot prove their identity (which has massive implications in not just banking but education as well)
• 2 billion people worldwide do not have a bank account or access to a financial institution
• Identity fraud is estimated to cost the UK millions of euros annually.

Read more at The Linux Foundation

Source

Should kids be technically literate? Of course! Is the best way to teach them this skill by turning them into programmers? Well, that’s a tougher question.

First, to be blunt, in much of the world, even in affluent areas, schools are not equipped to handle this task. Aside from lacking the physical technology, many also are lacking in adequate staffing resources in order to teach programming courses.

Second, it’s important to note that computer science and programming are not the same thing. Both are valuable, but in an academic program, it may actually be equally useful to teach computer science and formal logic, depending on what course of study a student wishes to pursue.

Third, programming and computer literacy are not the same thing, either. It’s entirely possible to be a computer power user without knowing how to program, and equally possible to be a programmer who doesn’t really know very much about the system that he or she is working on and how to optimize it for their use.

And fourth, instructional time is limited. Not everyone will end up using computer programming in their day jobs, so is taking time away from other subjects really going to lead to the best outcome?

That said, there’s still an argument to be made in favor.

The future is digital, and software is eating the world. To understand fundamentally how the world operates when algorithms are making decisions instead of humans requires some basic understanding of what an algorithm is and how it is created. Programming isn’t just about making things, it’s about understanding how things are made.

And the world frankly needs more programmers. There’s simply more and more code that needs to be written and managed than ever before, and while AI and automation might change what programmers are working on, it won’t change the need for them.

But further, understanding at least the basics of programming is important to being able to fully reap the benefits of open source. Having the code available to review, edit, and share under an open license is important, but can you really make use of the full power of an open license if you’re locked in by your own inability to make the changes you wish to make?

There are plenty of good reasons to take both sides.

What do you think? Should every kid today be learning to program? Why or why not?

Source

Planetary Annihilation: TITANS, the massive scale RTS now being continued by the new Planetary Annihilation Inc had another small patch recently to further improve it.

After the recent update to add in more multi-threading, they’ve expanded it a step further. Released on Friday last week, update 112314 added in experimental multi-threading on official servers, performance and memory usage improvements to navigation cost cells, more logging so they can find issues, plenty of AI improvements, some server bugs have been fixed along with modding adjustments and making orbital attack lines in the orbital path visualiser more visible.

I’m really quite impressed how quickly they’ve come back to continue improving this RTS. They’ve got a lot more improvements to come, as they haven’t upgraded the software behind various parts of the game yet like the UI system and so on.

It’s quite different to any other strategy game, especially since the maps are based across entire planets you scroll around. I love the fact that the mini-map is essentially another game window which you can set to watch any point you want, it’s very cleverly done.

Find it on Humble Store and Steam. With the current price, Humble seems cheaper than Steam.

Source

One of the best things about working at the Linux (or similar OS) command line is the use of pipes. In simple terms, a pipe takes the output of one command and sends it to the input of another command. You can do a lot with a pipe, but sometimes it is hard to work out the right order for a set of pipes. A common trick is to attack it incrementally. That is, do one command and get it working with the right options and inputs. Then add another command until that works. Keep adding commands and tweaking until you get the final results.

That’s fine, but [akavel] wanted better and used Go to create “up” — an interactive viewer for pipelines.

Pipe Philosophy

Pipes can do a lot. They match in with the original Unix philosophy of making each tool do one thing really well. Pipe is really good at allowing Linux commands to talk to each other. If you want to learn all about pipes, have a look at the Linux Info project’s guide. They even talk about why MSDOS pipes were not really pipes at all. (One thing that write up doesn’t touch on is the named pipe. Do a “man fifo” if you want to learn more for now and perhaps that will be the subject of a future Linux Fu.)

This program — called up — continuously runs and reruns your pipeline as you make changes to the pipe. This way, every change you make is instantly reflected in the output. Here’s the video, here’s a quick video which shows off the interactive nature of up.

Installing

The GitHub page assumes you know how to install a go program. I tried doing a build but I didn’t have a few dependencies. Turns out the easy way to do it was to run this line:

go get -u github.com/akavel/up

This put the executable in ~/go/bin — which isn’t on my path. You can, of course, copy or link it to some directory that’s on your path or add that directory to your path. You could also set an alias, for example. Or, like I did in the video, just specify it every time.

Perfect?

This seems like a neat simple tool. What could be better? Well, I was a little sad that you can’t use emacs or vi edit keys on the pipeline, at least not as far as I could tell. This is exactly the kind of thing where you want to back up into the middle and change something. You can use the arrow keys, though, so that’s something. I also wished the scrollable window had a search feature like less.

Otherwise, though, there’s not much to dislike about the little tool. If writing a pipeline is like using a C compiler, up makes it more like writing an interactive Basic program.

Source

SDL stands for Simple DirectMedia Layer and it’s an open source multimedia library written in C and designed to provide low level access to mouse, keyboard, audio, joystick, 3D graphics hardware via Direct3D and OpenGL.

Used in many Humble Bundle games or Valve’s award winning catalog

These days, SDL is heavily used by emulators, video playback software, as well as numerous popular games, including the award winning Linux port of “Civilization: Call To Powe,” many Humble Bundle games, and Valve’s award winning catalog.

Runs on all mainstream operating systems

Simple DirectMedia Layer runs on numerous operating systems, including the mainstream GNU/Linux, Microsoft Windows and Mac OS X ones. The BeOS, BSD (FreeBSD, OpenBSD), BSD/OS, Solaris, IRIX, QNX OSes, as well as the Android and iOS mobile operating systems are also supported. Supported hardware platforms include 32 and 64-bit.

Getting started with SDL

SDL is usually available for download on numerous Linux kernel-based operating systems, through their official software repositories. Installing it using the latest source package, which is distributed for free on Softpedia, is easy as pie.

Download and save the archive on your Home directory, unpack it, open a Terminal app and navigate to the location where you’ve extracted the archive file (e.g. cd /home/softpedia/SDL2-2.0.3).

Run the ‘./configure && make’ command to configure, optimize and compile the program. After a successful compilation, run the ‘sudo make install’ command as a privileged user to install SDL system wide.

Under the hood

A quick look under the hood of the SDL project, will inform us that it is written in the C programming language and that it works natively with C++. Bindings for other programming languages are also available, supporting the popular Python, Ada, Java, Lua, Eiffel, ML, PHP, Perl, Pike, Ruby, and C#.

Source