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A site for Linux lovers worldwide. For newbies, system engineers, administrators, and everybody in between. We cover all things Linux, plus various programming languages, including Python, Javascript, and PHP.

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How to Convert a USB Printer to Wireless with a Raspberry Pi

How to Use a Raspberry Pi for Digital Signage

The Worst Things You’ll Probably Google As a Programmer on Linux

How to Build a Raspberry Pi Internet Kiosk

Browsing the Internet on a 1989 Macintosh II with a Web Rendering Proxy

Limit CPU usage of Linux process

October 31, 2020July 3, 2012 by Stefan Durand

cpulimit is a small program written in C that allows to limit CPU usage by Linux process. Limit is specified in percentage so it’s possible to prevent high CPU load generated by scripts, programs or processes. I found cpulimit pretty useful for the scripts running from cron, for example I can do overnight backups and be sure that compression of 50GB file via gzip won’t eat all CPU resources and all other system processes will have enough CPU time. In most of Linux distributions cpulimit … Read more

Top 5 Password Managers for Linux

June 23, 2022May 16, 2012 by Stefan Durand

In this post you will find set of password managers for Linux which provides secure storage for your passwords for sensitive data. If you still keep the passwords in plain text then you must consider one of available password managers so this article is for you. KeePassX KeePassX has been a very popular and famous password manager for Linux for a very long time and still trusted by pretty big number of users. When user launches the KeePassX password manager first it requires to set … Read more

Grub Fallback: Boot good kernel if new one crashes

October 31, 2020April 24, 2012 by Stefan Durand

It’s hard to believe but I didn’t know about Grub fallback feature. So every time when I needed to reboot remote server into a new kernel I had to test it on local server to make sure it won’t panic on remote unit. And if kernel panic still happened I had to ask somebody who has physical access to the server to reboot the hardware choose proper kernel in Grub. It’s all boring and not healthful – it’s much better to use Grub’s native fallback feature. … Read more

Why Mosh is better than SSH?

October 31, 2020April 11, 2012 by Stefan Durand

Mosh (stands for Mobile Shell) is replacement of SSH for remote connections to Unix/Linux systems. It brings a few noticeable advantages over well known SSH connections. In brief, it’s faster and more responsive, especially on long delay and/or unreliable links. Key benefits of Mosh Stays connected if your IP is changed. Roaming feature of Mosh allows you to move between Internet connections and keep Mosh session online. For example, if your wifi connection changes IP you don’t need to reconnect. Keeps session after loosing connection. … Read more

Attach ISO image stored in XenServer local storage

October 31, 2020April 6, 2012 by Stefan Durand

Citrix XenServer is powerful hypervisor that is based on Linux (Redhat/Centos/Fedora family) and competes with Vmware ESXi and offer wide range of virtualization features for data centers. In general you can do a bare-metal installation of XenServer to your hardware server and create multiple virtual machines (VMs) inside XenServer host. Obviously you’ll need to have the possibility to boot VM from DVD-Rom to start installation of, let’s say, Linux Mint. You can do it using hardware DVD-Rom of the host XenServer or attach ISO image and … Read more

Track Cisco BGP peers using Nagios

October 31, 2020April 5, 2012 by Stefan Durand

Few will deny that monitoring of Cisco devices is essential part of sysadmin’s job. I personally use Nagios to track states of BGP neighbors on Cisco routers so if one of peers goes down I’ll receive a phone call from Nagios. You may have redundant network topology but it still makes sense to know when peer goes offline, how often it happens and how fast failover router (if any) pick-ups the traffic from failed peer. There are a few plugins for Nagios to monitoring BGP … Read more

Top Open Source IP Address Management Software

October 31, 2020April 4, 2012 by Stefan Durand

In this post you will find top open source software for IP address management (IPAM). If you are sysadmin at organization that holds pool of IP addresses and allocates its parts to clients then you must use IP address management tools to track used, reserved, allocated or free IP addresses. It usually prevents an overhead and allows to have clear picture of IP addresses resources usage within an organization on the whole. For example, it may be useful to know how many free IP networks are … Read more

Top 5 Linux Monitoring Tools. Web Based.

June 23, 2022March 22, 2012 by Stefan Durand

Linux system monitoring is one of the most important tasks for every sysadmin: it is crucial to know everything about system including CPU load, network traffic statistics, memory consumption, logged in users, availability of disk free space or service. And it’s inevitable that something breaks or goes down from time to time so usually it’s just better to know it happened from Linux monitoring system’s alert rather than from angry user. Believe me, it is true. In this article I’ve listed top 5 web based … Read more

Wget Cookies: Download Protected Content

October 31, 2020March 20, 2012 by Stefan Durand

Most of Linux users are using wget from time to time, sometimes even when they don’t know about it – many GUI download managers for Linux are based on wget. Anyways wget is command line tool for downloading files over HTTP, HTTPs and FTP protocols within single session. It works like a charm with default settings for downloading simple static files, at the same time if content is protected by cookies and/or referrer then wget may seem useless but it’s actually not. For example, imagine … Read more

Fix socket timeouts in Nagios

June 23, 2022March 16, 2012 by Stefan Durand

As any other monitoring system Nagios can produce false alarms. Usually it happens when Nagios fails to get the reply from the host being monitored during some pre-defined timeout. In order to mark service as down Nagios does three checks and if all of them are failed then the service is marked down and administrator will got an alert about its critical status. At the same time even if one of those checks fails Nagios will report administrator about it depending on configuration (e-mail, twitter, … Read more