Mar 032014

Article by me, first published on

Whether you are a system administrator or a developer, sometimes you need to consider the use of memory in GNU/Linux processes and programs. Memory is a critical resource, and limited memory plus processes that use a lot of RAM can cause a situation where the kernel goes out of memory (OOM). In this state Linux activates an OOM killer kernel process that attempts to recover the system by terminating one or more low-priority processes. Which processes the system kills is unpredictable, so though the OOM killer may keep the server from going down, it can cause problems in the delivery of services that should stay running.

In this article we’ll look at three utilities that report information about the memory used on a GNU/Linux system. Each has strengths and weaknesses, with accuracy being their Achilles’ heel. I’ll use CentOS 6.4 as my demo system, but these programs are available on any Linux distribution.

Continue reading »

flattr this!

Feb 192014

Original article by

Sometime a process “hang” both if you are using Gnu/Linux on your desktop (maybe a game ?) or as server, in these cases the best thing to do it’s to terminate that process, that probably is using precious resources, the basic commands to do this from a terminal are kill and killall.

killall is a tool for ending running processes on your system based on name. In contrast, kill terminates processes based on process ID number or “PID.” kill and killallcan also send specific system signals to processes. Use killall and kill in conjunction with tools including ps to manage processes and end processes that have become stuck or unresponsive when necessary.

Continue reading »

flattr this!

Nov 102013


Linux is much better at multitasking processor-intensive tasks than Windows. I remember how virus scanning used to make by old Windows PC almost unusable. Linux is much better, but sometimes bad things happens ! Perhaps a plugin of your browser is using all the CPU, or some bad software is freezing your system, or Apache it’s eating up all your resources on your server.

If you have seen some situation like these, don’t worry anymore, you don’t need to kill all the offending processes, restart your graphical session, or even worse restart the computer, you can simply put the specific process in “PAUSE” and analyse the situation, in some cases you could find the cause of a poor performing process, or just restart it in a second moment, maybe after you have saved all your works, when you can give to that process all the CPU.
Continue reading »

flattr this!

Understanding the Top command on Linux

Article by AlexioBash published on his website about ArchLinux in italian. Know what is happening in “real time” on your systems is in my opinion the basis to use and optimize your OS. On ArchLinux or better on GNU/Linux in general the top command can help us, this is a very useful system monitor that is really easy to [...]

The Life of a Process on Linux

Article by Santosh Sivaraj, originally published on Introduction The computer system is becoming a complex beast which cannot be tamed easily. In the new world the operating systems have become too big and complex for one to learn everything in depth. Most new aspiring system programmers do not have a picture of what is [...]