Unix News

Database administration encompasses such tasks as installing and configuring the DBMS, backing up the data, adding users and setting their various permissions, applying updates or new capabilities to the system, and similar tasks. If you just have yourself and a fairly small lab to deal with, it's not too bad. But organizations often hire one or more database administrators to do this work full time; even a smallish project, if it's critical and the budget exists, can benefit from the attention of a professional database administrator. read more.

The virtual file system is an abstraction of a physical file system implementation. It provides a consistent interface to multiple file systems, both local and remote. This consistent interface allows the user to view the directory tree on the running system as a single entity even when the tree is made up of a number of diverse file system types. The interface also allows the logical file system code in the kernel to operate without regard to the type of file system being accessed. For more information on the logical file system. read more.

System calls are functions that a programmer can call to perform the services of the operating system. There are several online books that describe them at some length, for example Programming in C. Unix manual pages are probably the first stop. They are often referred to as "man pages," because they are accessed with the man command. The manual pages are divided into eight sections. They are organized as follows: read more

When Linus was first creating Linux, he used the Minix filesystem. This served initial development well but soon there was a need for something bigger and better. In April 1992, the Extended File System was created. Although solving the problems of Minix, it had problems of it's own so a successor was created. This new filesystem was known as the Second Extended File System or Ext2 FS (or EXT2). read more.

You have written some Perl scripts already, and when somebody asks you how to reverse a string, you'll answer: "That's easy, just call reverse in scalar context". And of course, you're right - if you're only considering ASCII chars. But suppose you have an UTF-8 environment: read more.

This document describes how to set up PC-BSD v1.4 beta. PC-BSD is released under the BSD license. This document comes without warranty of any kind! I want to say that this is not the only way of setting up such a system. There are many ways of achieving this goal but this is the way I take. I do not issue any guarantee that this will work for you!

Each distribution has some specific tools to build a custom kernel from the sources. This article is about compiling a kernel on a Debian Etch system. It describes how to build a custom kernel using the latest unmodified kernel sources from www.kernel.org (vanilla kernel) so that you are independent from the kernels supplied by your distribution. It also shows how to patch the kernel sources if you need features that are not in there.

djbdns is a very secure suite of DNS tools that consists out of multiple parts: dnscache, a DNS cache that can be used in /etc/resolv.conf instead of your ISP's name servers and that tries to sort out wrong (malicious) DNS answers; axfrdns, a service that runs on the master DNS server and to which the slaves connect for zone transfers; and tinydns, the actual DNS server, a very secure replacement for BIND. more ...

Are you using SSH in the best way possible? Have you configured it to be as limited and secure as possible? The goal of this document is to kick in the new year with some best practices for SSH: why you should use them, how to set them up, and how to verify that they are in place. All of the examples below assume that you are using EnGarde Secure Linux but any modern Linux distribution will do just fine since, as far as I know, everybody ships OpenSSH.

This article is intended for people who have some computer expertise, even if it's Windows-only. At a minimum, you should be comfortable with the MS-DOS command line in Windows and have done a bit of Windows Registry editing to give you some experience with configuration files.

You want to set up a POP3 mail server—nothing fancy, just a basic server for Internet mail for a single domain, with TLS/SSL support for more secure logins. Here are the requirements: read more...

This document discuses configuration of wonderful tool called AWStats. It will guide you to configure and install it properly.

Welcome to the next step in studying for the Linux certification exam 301. This tutorial series serves as a comprehensive self-study guide so you can take the exams with confidence. And even if you're not preparing for Linux certification at this time, this series helps you build fundamental skills on Linux systems administration. In this tutorial (the second in a series of six tutorials on exam 301 topics), Sean Walberg walks you through installing and configuring a Lightweight Directory Access Protocol (LDAP) server, and writing some Perl scripts to access the data. By the end of this tutorial, you'll know about LDAP server installation, configuration, and programming.

So what's new with Linux at CES this year? That's our question. If you have the answers, let's have 'em. Because we'll be there on a Linux Hunt, just like we are every year. The difference this time is that we'd like to make this a Team Thing. read more.

Setting up a file server doesn't need to be complicated. With three desktop machines (Kubuntu, Win XP and a testbed, which is currently running ReactOS) and a laptop (Xubuntu) in use at home, our IT is reaching small office proportions, and like many small offices, we run into file sharing problems. Peer-to-peer networking is fine when all the machines are on, but inevitably it happens that the file I want is on a PC that isn't running. Even worse, it be on my testbed machine that is currently in pieces or undergoing yet another upgrade. So, we need an always-on server that any of us can access any time, but if it is always on, it needs to be quiet, reliable and cheap to run. These requirements rule out Pentium 4 (too hot and power-hungry) and Windows (needs rebooting too often). Fortunately, I just happen to have a Pentium III of no great distinction that sports a massive passive cooler, and I'm a bit of a Linux enthusiast. Apart from stability, Linux has several other adv...

Now that you've seen what a firewall chain listing looks like and what formatting options are available, we'll go through brief lists of INPUT, OUT, and FORWARD rules. The sample rules are representative of some of the rules you'll most likely use yourself. read more.

Ubuntu is a great server and desktop distribution for the GNU/Linux® operating system, but did you know that it's also ideal for handheld and mobile embedded devices? Ubuntu's latest release, Gutsy Gibbon, now includes support for the embedded and mobile spaces with the Ubuntu Mobile and Embedded (UME) project. Get to know the UME project, and find out how to get started. read more .

Two entries in /proc contain useful system statistics. The /proc/loadavg file contains information about the system load. The first three numbers represent the number of active tasks on the system—processes that are actually running—averaged over the last 1, 5, and 15 minutes. The next entry shows the instantaneous current number of runnable tasks—processes that are currently scheduled to run rather than being blocked in a system call—and the total number of processes on the system. The final entry is the process ID of the process that most recently ran. The /proc/uptime file contains the length of time since the system was booted, as well as the amount of time since then that the system has been idle. Both are given as floating-point values, in seconds. read more...

it's a simple job to do a cron job. This month, I thought I'd take another sidetrack. (You knew that entrepreneurs all have ADD, right?) So, it should be no surprise that to me, the fastest way from point A to point B is, um, what were we talking about? read more .

The XO laptop (of the One-Laptop-Per-Child initiative) is an inexpensive laptop project intended to help educate children around the world. The laptop includes many innovations, such as a novel, inexpensive, and durable hardware design and the use of GNU/Linux® as the underlying operating system. The XO also includes an application environment written in Python with a human interface called Sugar, accessible to everyone (including kids). Explore the Sugar APIs and learn how to develop and debug a graphical activity in Sugar using Python.

Examine methods for reporting on e-mail usage and getting detailed statistics on mailbox use. E-mail logs can provide a wealth of information about your users and their e-mail habits, including how often and frequently they use their e-mail. Depending on your UNIX® systems, you might even be able to glean more detailed information, such as identifying which users are using their folders effectively and who could benefit from further training and advice.read more on IBM developers.

If you would like to copy a set of files for all existing users, use the following scripting trick. It will save lots of manual work. First you need to grab all user names from /etc/passwd file using cut comand: read more .