Small and at the same time great article from Steve on http://www.debian-administration.org/.
—
If you run a multi-user system it can increase security if you hide the display of running processes, and their arguments, which belong to other users. This helps avoid problems if users enter passwords on the command-line, and similar.
Article by me, first published on Openlogic.com
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.
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 »