Mar 032014
 

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.

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Mar 012014
 

logoMPD, short for Music Player Daemon, is a flexible, powerful, server-side application for playing music. Through plugins and libraries it can play a variety of sound files while being controlled by its network protocol.

It is also used for one of the two purposes, as local daemon or as network daemon. MPD don’t use many resources. It is designed to make its job in background playing music from its database.

For connecting with MPD and managing music there are many options and clients. CLI clients, GTK clients, Qt clients and even from VI.
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Feb 192014
 

Original article by http://blog.shineservers.com/

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.

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Feb 102014
 

An old article by Todd Partridge (Gently) but still really useful if you are writing some bash scripts and want them more readable with some colors:

Users who have been using Linux for awhile often learn that creating a basic script is a good way to run multiple, often-repeated commands. Adding a little color to scripts can additionally provide nice feedback. This can be done in a fairly straight-forward way by using the tput command.

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Jan 292014
 

Often one wants a shared access to files across machines. Traditionally one uses the network file system (nfs). The network file server works as follows: There is an nfs server that exports some directories in its filesystem hiearchy to various nfs clients that mount these directory over the network into their file system hierarchy. As a result, each of the clients shares the directories exported by the nfs server.

However a lot of times you just have to mount a directory from a server to your local computer and in these cases NFS it’s not so useful, sshfs it’s much better

Sshfs is a filesystem client based on the SSH File Transfer Protocol. Since most SSH servers already support this protocol it is very easy to set up: i.e. on the server side there’s nothing to do.  On the client side mounting the filesystem is as easy as logging into the server with ssh.

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