renyborges

A Quick Explanation About the Output from the Free Command in Linux

August 22, 2020

First I would like to quickly explain about Buffer and Cache, so things can make sense up ahead :)
Difference between Buffer and Cache:

Buffer is a temporary location for storing data for a particular application and this data is not used by any other application.

Cache is a memory location to store frequently used data for faster access.

Both are temporary store for your data processing. However memory specified as buffer/cache can be made available when an application needs it, so we count it as 'free/available' memory, but Linux counts it as used memory.

Memory that is	You'd call it	Linux calls it
used by applications	Used	Used
used, but can be made available	Free (or Available)	Used (and Available)
not used for anything	Free	Free

The available you see in the output is an estimate of the amount of memory that is available for starting NEW applications, without using the swap memory.

So, to know exactly how much memory RAM is being used we take the 'used' memory number (which consist of really used memory RAM by the system plus memory used for buffer and cache), and subtract by the number in 'buff/cache' (which is used memory, but can be made available when it's needed.), and we can see that only 1036MB is being really used.

used: 4465

buff/cache: - 3159 (can be made available)

really in use: 1306MB around 1.31GB

Now to see how much memory is really available in total for use, we take the 'total' number of memory RAM on your system, and subtract the real used RAM of above.

total: 8241

real used RAM: - 1306

Free RAM 6935MB around 6.94GB

Conclusion

So next time you see only a couple of Megabytes left in the column ‘available’, do not despair, you might still have plenty of free RAM to be taken from the Buffer/Cache.

https://youtu.be/dmR9pWA3nwY

Posted by Rena Borges / Renata Shaw. Posted In : Linux

Linux Directory Structure Explained

April 10, 2020

Apart from the home folder, you need administrator privileges to access the other folders. Although you can look.

/ = This is the root directory which should contain only the directories needed at the top level of the file structure.

root folder - home directory for the super user = That's where the root home users directory is if you have a root user account activated on your system. This is different from the / directory, which is the system's root directory.

/bin - essential binary c...

Posted by Reny Borges / Renata Shaw. Posted In : Linux

Explaining and Managing Service Management Facility (SMF) - Oracle Solaris Administration

April 1, 2015

Service Management Facility (SMF) is a way to organize and manage the services in Solaris. It's a unified mechanism to manage the services Start / Stop, Restart services with dependencies. When the OS boot up the SMF run a Start-up Services Configuration for all the services with dependencies; Without Run Control (RC) scripts, it's easy to manage. If you come across a problem with one of the services you can take actions with the commands from SMF to manage the service. These actions can be...

Posted by Rena Borges / Renata Shaw. Posted In : Solaris

What is Boot Environment and How to Manage It

March 31, 2015

Boot Environment (BE) is a bootable instance of the image of the Oracle Solaris operating system and of any other software packages installed in this image. Think in your particular OS, let's say Windows 7, with all your programs and updates installed on it, creating a BE of this OS is to have all your programs and updates saved in a partition as a file, where you can boot in case the main one in use gets corrupted for instance. However, Boot Environment belongs particularly for Solaris be...

Posted by Rena Borges. Posted In : Solaris

Getting Information About Packages in Solaris - Image Packaging system (IPS)

March 31, 2015

The pkg list command will tell you if a package is installed, frozen, obsolete or renamed under the column IFO.

I "i" = Package is installed
F "f" = If a package is frozen, you can only install or update to packages that match the frozen version.
O "r" = It indicates that package has been renamed.
O "o" = It indicates that package is obsolete. You cannot install a package that is marked obsolete.

reny@solaris11_2:~$ pkg list gedit
NAME (PUBLISHER) VERSION ...
Continue reading...

Posted by Rena Borges. Posted In : Solaris

Identifying Processors in Solaris - psrinfo / psradm

March 27, 2015

Usually a solaris box has several processors on-board. Here I show you some simple commands like how to enable / disable / spare the processors using psradm.
When comes to troubleshoot hardware issues it comes handy.

-bash-4.1$ psrinfo
0       on-line   since 02/05/2015 13:36:38
1       on-line   since 02/05/2015 13:36:41
2       on-line   since 02/05/2015 13:36:41
3       on-line   since 02/05/2015 13:36:41
4       on-line   since 02/05/2015 13:36:41
5       on-line   since 02/05/2015 13:36:41
6   ...
Continue reading...

Posted by Rena Borges. Posted In : Solaris

Changing the host-name in Solaris 11

March 27, 2015

If would like to change the host-name in Solaris 11, it's quite simple and much simpler nowadays. You can basically do it in only 2 steps.

1 - First of all you should check the current properties of the system using svccfg:

reny@solaris11_2:~$ svccfg -s system/identity:node listprop config
config                       application
config/enable_mapping       boolean     true
config/ignore_dhcp_hostname boolean     false
config/nodename             astring     solaris11_2
config/loopbac...

Posted by Rena Borges. Posted In : Solaris

What can you do with a 3D Printer?

February 21, 2014

You have probably heard about 3D printers, but probably does not have one at home. These machines are becoming more popular and leading to profound changes in the market to offer a choice between mass production and customization of industry and manufacturing. 3D printing is the boundary between the physical and virtual, the digital and the real world.

However, it is misleading to think that 3D printing is something new, the technology has existed for 30 years. What happened in recent years ha...

Posted by Rena Borges. Posted In : New Technologies

SanDisk launches pendrive for Android Smartphones and tablets

February 13, 2014

Having more storage space on tablets and Smartphones or to be able to use files that are on USB sticks are some of the difficulties for users of mobile devices. To be able to download these files with ease, the manufacturer SanDisk introduced on Tuesday ( 11 ) the stick "Ultra Dual USB Drive" with USB input - to connect to a PC, and a micro - USB, which is attached to mobile phones and tablets.

According to the company, the flash drive allows you to store and backup data, and free up mor...

Posted by Rena Borges. Posted In : smartphone

How to install a fully portable desktop on a USB for on-the-go access

August 18, 2013

Porteus is a portable Linux operating system which is able to be installed on a portable USB device.

"Porteus manages to offer a full-blown distribution by installing in a compressed state (to keep its footprint small). During the boot process, it uncompresses and boots very quickly. Porteus also offers a package manager so you can easily install more applications. The package manager has a dedicated Porteus repository to select from, but you can install applications from any repository...

Posted by Rena Borges. Posted In : Linux

« Newer posts

Older posts »