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One concern when users FTP into your server, is that by default users who have accounts can roam your server to view contents of files. VSFTPD by default does not allow user logins, it allows anonymous by default. Anonymous users by default are locked into the directory that they login to. This is exactly what you would want. However, if you set up user FTP accounts you will probably want to limit those users so they can only access their own files and not other users. In order to achieve this you must place them in a chroot jail.

When you are using a FTP server you can connect using either Active or Passive connections. Each has advantages and disadvantages. When you set up FTP, in this example using VSFTPD, you need to make this connection decision. Active connections are safest for the server but at times may not work for some clients. Passive connections may not be the safest for the server but usually work well for the clients. In addition, these factors must be taken into account with the firewall. This is where connection tracking can be helpful.

The Parsix Linux distribution is derived from KANOTIX, based on the Debian testing branch, and developed by a team in Iran. The distro comes as a live CD with English and Persian languages installed by default and many others available. According to the release announcement features of the new Parsix 3.0 include GNOME 2.26.3, Linux 2.6.29.6-based Kernel, the installer supports separate /home partition, ext4 file system and GRUB 2, SquashFS+Lzma compression for the live CD and much more. After seeing the amount of changes to this release and remembering positive reviews of Parsix 1.0 and 2.0, I burned the .ISO to CD and got started.

UFW or Uncomplicated Firewall, is a text based firewall that works with iptables. UFW is designed to be an easier way to manage a firewall from the command line. Whether this is easier than learning iptables or not, you can decide. But UFW comes partially set up when you install Ubuntu. Now, it is not activated by default so you have no protection but some basic settings that are in place when you do start up UFW.

This Ubuntu installation guide is available to anyone for free. Once you've completed this guide you'll be able to install Ubuntu and have a good understanding of the options on each step of the install. Users should also be able to perform a manual installation of Ubuntu after using this Ubuntu installation guide. A step-by-step video tutorial is included with this guide.

The quotas mini-course is designed to help you implement quotas for users and groups. Quotas are a way to guarantee resources for your users. The guarantee of resources to your users is fundamental to good system administration. When users run out of space there is always trouble and you can be sure as administrator that trouble will be pointed at you. Whenever you implement quotas with users it is a good idea to create soft limits which provide them a warning for 7 days but during that time they can still save.

Building Postfix from source can be a rewarding experience with great results. This post will show you how to do a basic build and then how to build in additional features using tutorials.

Labs are step-by-step exercises that students can perform to learn how to perform a task. Labs can also provide the aspect of experience if it is repeatedly done, which creates confidence.

If you haven't played with Slackware within the past couple of years, you may still believe that the word “easy” doesn't go well with the words “update” and “package management”. But, two fairly new utilities, “slackpkg” and “sbopkg”, may help to change your mind.

If your interest is in becoming a Linux administrator one skill you must have is the ability to network servers and understand the interaction between servers. You will also need to know how to build servers using RAID, LVM and optional file systems. These skills can be practiced on a virtual network of practice servers. You can build a training network using one workstation. I use several options for building a training network; VMWare Player, OpenVZ and VirtualBox.

This Nagios Mini-Course shows you how to configure Passive Checks from clients which are sent to a central Nagios Server. Passive checks use the NSCA or Nagios Service Check Adaptor which is an add-on for the Nagios Server. You can write custom scripts to evaluate applications and send the output to a central Nagios Server. Passive Checks are often used when a firewall prevents Nagios from obtaining information from the client.

There are default mailbox sizes which may lead to mail delivery failure when you go beyond the defaults. In order to avoid problems you need to understand the difference between mailboxes and virtual_mailboxes as well as know the default sizes and how to adjust them. Here is the error that you want to avoid:

I have discovered that one of the most powerful avenues of learning is the ability to ask questions. When people can ask questions learning occurs. Why is asking questions so important? Well it is the old agony of getting stuck on one small thing.

moonOS 3.0 is based on Ubuntu 9.04 and uses the Enlightenment window manager. The moonOS 3.0 release includes many improvements making this distro even faster and easier to use than previous versions. Take a look at some things moonOS can do out of the box with this quick review, screenshot gallery, and moonOS overview video.

Slackware is becoming a real favaorite for me. It's fast, nimble and rock solid. However, I have a HP Mini 100 with a Broadcom 4312 (rev.01) wireless card. If you know anything about this card you know this is bad news....real bad news. But I decided to write this article to create some encouragement to those of you who are ready to leave Linux because you cannot get wireless going. It is possible, but it may not be easy. One thing for sure ...it is worth it.

The virtual classroom is the future of Linux Training. As Linux grows and and more companies need Linux Server Training the virtual classroom will gain more acceptance based on the advantages that a company can create using virtual training. The virtual classroom consists of live interaction between instructor and student using VOIP and allowing students to login to the instructor’s screen to view demonstrations. These are the keys to any successful training, especially as it is related to acquiring skills on Linux servers.

This course provides a basic understanding of GRUB and gives you some illustrations on how to secure it and fix several common problems. GRUB stands for Grand Unified Bootloader and was created in 1995 by Erich Boleyn as he wanted to have a multiboot option. Intel based motherboards must be started with a 16-bit operating system because of a limitation to 640 kilobytes of RAM at startup. GRUB is used to facilitate the 16-bit requirement and load the 32-bit Linux kernel. The AMD CMOS is 64-bit so it can load the 64-bit kernel for Linux. In order for GRUB to work it must use a three step process on CentOS.

If you’re running newer hardware, there are some definite advantages to installing a 64-bit operating system. But, if you still need to run any 32-bit applications, you’ll need to have the 32-bit support libraries installed. Different Linux distros handle this in different ways.

Scripts are files that contain shell commands which may be short or can be very complex. Scripts just make it easier because you can invoke one command to run all of the commands in the script. Here instead of using 8 separate commands you can use one command to execute all of them. This course is in a series of mini-courses to help you with Bash Shell Scripting. It is divided into several sections as you can see below. In addition, to help you in the challenge of learning bash shell scripting you will find a quiz at the end of each mini-course.

As Ubuntu popularity grows, more and more students are recognizing the added features and potential savings offered by an Ubuntu laptop. Netbooks and laptops are the students solution to computing because of obvious portability reasons. One thing many students find frustrating is the higher cost of laptops and netbooks compared to desktops with similar specs. The biggest reason that Ubuntu laptops can save you money over Windows laptops is that companies like Dell are able to lower the price of Ubuntu-installed laptops because they don’t have to pay for the operating system. Ubuntu can be added to almost any computer by creating and booting to an installation disk however for compatibility reasons buying pre-installed Ubuntu laptop may be the best choice for newbies.