Apr 122015
 

systemd is a suite of system management daemons, libraries, and utilities designed as a central management and configuration platform for the GNU/Linux computer operating system.
It provides a system and service manager that runs as PID 1 and starts the rest of the system as alternative to the traditional sysVinit.
systemd provides aggressive parallelization capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons,

It’s becoming the standard of all the major GNU/Linux distributions and at the moment it’s the default for Arch Linux, Red Hat Enterprise/Centos (version 7), Fedora, Mageia and Suse Enterprise, it’s planned to be used on Debian 8 and Ubuntu 15.04.

There is a lot of people talking for and against systemd on the net as some see it as too intrusive, complex and against the Unix philosophy to keep things simple and make them do just one task.

Using Red Hat 7 at work and Arch Linux on my laptop I’ve started to use it and I must agree that it’s not so simple in the start, but let’s try to take the good thing from it and in this article I’d like to show you some commands that you can use with systemd to manage the processes on a GNU/Linux system and that I’ve found really useful.
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Sep 132014
 

Systemd
Article by Stuart Burns first posted on Openlogic.com

With Red Hat Enterprise Linux 7 released and CentOS version 7 newly unveiled, now is a good time to cover systemd, the replacement for legacy System V (SysV) startup scripts and runlevels. Red Hat-based distributions are migrating to systemd because it provides more efficient ways of managing services and quicker startup times. With systemd there are fewer files to edit, and all the services are compartmentalized and stand separate from each other. This means that should you screw up one config file, it won’t automatically take out other services.

Systemd has been the default system and services manager in Red Hat Fedora since the release of Fedora 15, so it is extensively field-tested. It provides more consistency and troubleshooting ability than SysV – for instance, it will report if a service has failed, is suspended, or is in error. Perhaps the biggest reason for the move to systemd is that it allows multiple services to start up at the same time, in parallel, making machine boot times quicker than they would be with legacy runlevels.

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Oct 042011
 

Cgroups is present in the official Linux kernel 2.6.24 (late 2007), still he’s not much know or used (at least for what i know).
In this article I’ll give you an overview of this powerful Linux tool to control how much CPU, memory, disk I/O or network I/O each process or user can use in your server.

So in short cgroups it’s a feature to limit, account and isolate resource usage (CPU, memory, disk I/O, etc.) of process groups.
Let’s see how.

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Notes from RH: Virtual Experience

Notes from RH: Virtual Experience

Yesterday I followed the online event Virtual Experience, presented by Red Hat. The event was presented in 4 main areas :Red Hat Enterprise 6, Cloud Computing, Virtualization and Jboss, for an idea of the sessions available take a look here. I followed some of the sessions and from what I saw I had the impression that Cloud is the key word (or fashion) that is often repeated even in talks about  other  topics,  RH  surely   is betting a […]