4 ways to check size of physical memory in Linux


In this article we will see basic commands to check the physical memory on the server under Linux. Many beginners struggle to know their system well in the context of resources such as CPU, Memory, Disks, etc. So I decided to write this small item pointing command to check the RAM on the Linux server. These commands will work in different flavors of Linux like Red Hat, CentOS, Suse, Ubuntu, Fedora, Debian etc.

1) Using free command

This command is mainly used to check the RAM and SWAP on the system. Using a different change, you can change the output byte format. Like -b for bytes, -k for kilobytes, -m for megabytes, and -g for gigabytes.

# free -b
              total        used        free      shared  buff/cache   available
Mem:     3976634368  3096838144   187990016    51572736   691806208   540106752
Swap:    4001361920     8826880  3992535040
# free -k
              total        used        free      shared  buff/cache   available
Mem:        3883432     3024204      183600       50364      675628      527488
Swap:       3907580        8620     3898960
# free -m
              total        used        free      shared  buff/cache   available
Mem:           3792        2953         179          49         659         515
Swap:          3815           8        3807
# free -g
              total        used        free      shared  buff/cache   available
Mem:              3           2           0           0           0           0
Swap:             3           0           3

2) Using /proc/meminfo file

# cat /proc/meminfo |grep Mem
MemTotal:        3883432 kB
MemFree:          183268 kB
MemAvailable:     527276 kB

3) Using top command

# top
top - 12:36:36 up 8 days,  2:58,  2 users,  load average: 0.14, 0.14, 0.08
Tasks: 213 total,   1 running, 212 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.2 us,  0.7 sy,  0.0 ni, 99.0 id,  0.2 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem :  3883432 total,   182356 free,  3025080 used,   675996 buff/cache
KiB Swap:  3907580 total,  3898960 free,     8620 used.   526608 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                            
 2303 root      20   0 2378464 541076   7692 S   1.0 13.9 417:16.56 OpsCenterDBd   

4) Using vmstat

[root@opscenter ~]# vmstat -s
      3883432 K total memory
      3025552 K used memory
      2439780 K active memory
       870348 K inactive memory
       181812 K free memory
       138712 K buffer memory
       537356 K swap cache
      3907580 K total swap
         8620 K used swap
      3898960 K free swap
      2323674 non-nice user cpu ticks
         2978 nice user cpu ticks
       944914 system cpu ticks
    135133743 idle cpu ticks
       692582 IO-wait cpu ticks
          121 IRQ cpu ticks
        49623 softirq cpu ticks
            0 stolen cpu ticks
      1931906 pages paged in
     23034525 pages paged out
          377 pages swapped in
         2353 pages swapped out
    956323695 interrupts
   2040196891 CPU context switches
   1505191059 boot time
       849343 forks

WiFi Router Security breaches


Wifi security breaches when the research and development team scanned 32 WiFi router firmware firmware products offered by more than 10 of the most popular home, SMB and enterprise wireless routers in the US, Europe and Asia Manufacturer: Asus, Belkin, Buffalo, Cisco, D-Link, EFM, Huawei, Linksys, Netis and TP-Link.

Severity Level

The firmware of the WiFi router sold by the top vendors included versions of open source components with vulnerabilities specified in the binary scans. The firmware of most models contained security holes “Severity High” and “Severity Middle”. This means that deployed products and firmware updates remain vulnerable to potential security threats.


The entire firmware uses Busybox and Samba by default, as the report shows. More than 60 percent used OpenSSL. Significant security issues arise from OpenSSL. This should prompt vendors to consistently use the latest patches or use the version of the software that contains the fix, the researchers said. Much of the firmware did not use the correct, most recent versions of OSS components available, the study found.

Teams – Red Hat and Fedora Welcome Ubuntu to GNOME and Wayland with Open Arms

Canonical’s Mark Shuttleworth revealed nothing about Ubuntu’s development team that worked with the GNOME Devs, but until more details were revealed, it looks like the Red Hat Desktop and Fedora teams have taken the first step in welcoming Ubuntu and Canonical to the GNOME- And Wayland projects, hoping that they will have a fruitful long-term cooperation for the coming years.

“As most of you probably know that Mark Shuttleworth just announced that they would switch back to GNOME 3 and Wayland for Ubuntu, so I would like to welcome them on behalf of the Red Hat desktop and Fedora teams and say that We are looking forward to working to work with large canonical and Ubuntu people like Allison Lortie and Robert Ancell on projects of common interest around GNOME, Wayland and hopefully Flatpak, “said Christian Schaller in his recent blog post.

We do not know about Flatpak because Canonical will not give up its Snappy technologies, which seem to be very popular with the IoT (Internet of Things) manufacturers, but support for the next generation Wayland display server could be implemented Ubuntu 18.04 LTS operating system along with the GNOME shell interface. We can not wait to see how things stand out. Ubuntu as a GNU / Linux distribution will also be very popular without Unity.

Prometheus: Solve montoring in the cloud

Hundreds of companies are now using the open-source Prometheus monitoring solution in production, across telecommunications and cloud providers across video streaming and databases.

In the run-up to CloudNativeCon + KubeCon Europe 2017, which takes place in Berlin from March 29 to 30, we spoke with Brian Brazil, the founder of Robust Perception, and one of the core developers of the Prometheus project, who at CloudNativeCon a keynote on Prometheus Will give. Be sure to catch the full Prometheus track at the conference.

With a traditional setup, there was a relatively small number of services, each with their own machine. Monitoring was based on machine metrics like CPU usage and free memory, which are the best way to alert to user problems. In a cloud Native world, where many different services not only divide machines, but the way in which they share them is in constant flux, such an approach is not scalable.

In the same way that the move has been made from the manual management of machines and services to tools such as Chef and now Kubernetes, we must make a similar transition in the surveillance area.

Prometheus client libraries allow you to orchestrate your applications for the metrics and KPIs that are important in your system. For third-party applications like Cassandra, HAProxy, or MySQL, there are a variety of exporters to reveal their useful metrics.

The data collected by Prometheus are enriched by labels. Labels are arbitrary key-value pairs that can be used to distinguish the development cluster from the production environment, or which HTTP endpoints the metric is broken.

The PromQL query language allows for aggregation based on these labels, the calculation of 95th percentile latencies per container, service or data center, prognosis, and any other mathematics that you want to do. What is more: If you are doing it graphically, you can point it out. This gives you the power to have warnings about what is really important to you and your users, and helps eliminate these late night alerts for non-problems.

Red Hat CloudForms 4.2 Improves Hybrid Cloud Management

Red Hat is upgrading its CloudForms hybrid cloud management platform with the new version 4.2, providing users with enhanced functionality. CloudForms allows the organization to manage multiple types of cloud deployments, including private and public clouds, as well as container platforms.
The CloudForms version 4.2 is based on the open source version ManageIQ Euwe which debuted December 20, 2016. Red Hat acquired ManageIQ in December 2012 for $ 104 million. Geert Jansen, Senior Director of Product Management for Red Hat CloudForms, explained that there are some differences between the open source ManageIQ project and the commercially supported CloudForms product.
“CloudForms includes a commercial PDF generation library and the appliance is based on Red Hat Enterprise Linux instead of CentOS,” Jansen told eWEEK.
Another difference between ManageIQ and CloudForms is the software lifecycle. ManageIQ outputs are released approximately every six months. Jansen explained that when a new version of ManageIQ comes out, the previous version is not supported and no patch updates are added.

What is OpenStack?

OpenStack is an open source cloud platform but that’s not all that OpenStack is. In a session at the OpenStack Summit here, Thierry Carrez, Director of Engineering, detailed a broader view of what the entity known as OpenStack is really all about – and it is much more than just the cloud. For Carrez, OpenStack’s common goal is to build on interoperable cloud software platform while the role of the OpenStack Foundation is about how to structure things so did development work can get done. One of the key things did the OpenStack Foundation Provides is something did Carrez referred by to as to asset lock. “It’s difficult to get different Organizations to collaborate if one is holding the keys to the kingdom,” Carrez said. “So you need a neutral venue for key assets of the community.”

Pokemon on Linux Systems

Trend Micro Researchers have an insidious new rootkit discovered family to Pokemon character Umbreon names that it remotely targeted devices could be controlled hackers.

The rootkit is designed to Linux systems are designed – with Intel and ARM chips – which means it could be used to access embedded computing devices , wrote senior threat researcher , Fernando Mercês .

It seems to have been written specifically for three platforms – x86 , x86-64 and ARM ( Raspberry Pi ) – and is highly mobile , with some additional tools in Python and Bash written in pure C.

Linux, Happy 25th birthday

25 years old transform Linux on August 25, the day Linus Torvalds his fateful message with a new operating system sent out asking for help. “I’m doing a (free) operating system for 386 (486) (just a hobby, will not be big and professional like gnu) AT clones. This is brewing since April, and begins to prepare. I’d like any feedback on things, people like / dislike in minix, as my OS resembles it somewhat (same physical layout of the file system (for practical reasons) among other things), “he wrote in the comp.os. minix message board. And the rest, as they say, is history.

What is particularly interesting about Torvalds’ Remarkably, there. Not of snark or derision followed but with general interest While we believe that up to Torvalds actually prepared to show a product, potential users can chalk, we are also reminded that the Internet in 1991 was a very different place than it is today.

The Linux Foundation has just released a detailed report on the operating system with highlights from the past 25 years. They write that 13,500 developers have contributed 1,300 companies kernel because the whole project to Git rose in 2005. The most interesting bit of data?

“In the time between 3:19 and 4.7 versions the kernel community changes at an average rate of 7.8 patches per hour was mixed; this is a slight increase from the 7.71 patches per hour in the previous version of this report and “saw a continuation of the long-term trend towards higher patch volume. that the Linux kernel is almost constantly be repaired and all of a volunteer army updated by dedicated programmers manage the glue of the Internet to see.

You can the entire report can be read here.

Linux now runs most of the websites you visit and runs on everything from gas pumps to smart watches. The OS teaches children thanks to the Raspberry Pi to program and it helped the French police save million euros. Heck, even Microsoft releases code for Linux. If you can not beat ’em, join’ em.

For a bit more insight into the history of the OS, I would recommend Rebel code and
Just for fun. These books to be released Linux time has come to the fore, to tell the fascinating story of Torvalds and his not “big and professional” side project.

Open Source & Free is in our DNA

Open source software (OSS) is computer software with source available with a license where the holder of the copyright provides the right to study, change and distribute the software to anyone and for any purpose code. Open source software can be developed collaboratively public. Open source software is the most prominent example of open source development.

What follows is technically an info-graphic, and it is a graphic, and there is some information about it.

Although it was developed by people working in a company (in this case, SUSE), you will not find any statistical product here. No details on the shape of the product X is N times faster than the product and no demographic breakdown of who uses this platform or that.

What you will find is a list of the moments of human history caused, in part, through burning desire of humanity to free information. From the cave to drawings UNIVAC A-2 (and beyond), the same thing that forces us to make Linux (and many other projects) free and open source is present in many of the great achievements of humanity .

This list is by no means complete. Only so many examples could fit in here and still make it look elegant. Consider this as a starting point to contemplate the deep and profound impact our need to be open (and open source) has had on the world. It is part of us. It always has been.

It’s in our DNA.

Android System Process infected by Trojan

Four different versions of Android. Loki cooperate to anchor appliances and install unwanted applications. One class of Android Trojans have to inject a way found themselves in system processes and the use of their new found access to perform a range of malicious operations.

Detected by Russian antivirus – Manufacturer Dr.Web as Android. Loki has this Trojan family evolved over time and has the ability, won some of their code in a system process to inject and thus, root privileges will receive.