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Search results for Optimizing Desktop Performance, Part III

Linux Xen Virtualization and Linux Clustering, Part 1
Post date: January 21, 2006, 01:01 Category: System Views: 101
Tutorial quote: Have you heard about Xen virtualization and want to get some hands-on experience? Do you want to experiment with Linux clustering but only have a single computer to devote to the cause? If you answered yes to either of these questions, keep reading.

In this article, I briefly introduce the concepts of Xen virtualization and Linux clustering. From there, I show you how to set up multiple operating systems on a single computer using Xen and how to configure them for use with clustering. I should point out that a cluster implemented in this manner does not provide the computational power of multiple physical computers. It does, however, offer a way to prototype a cluster as well as provide a cost-effective development environment for cluster-based software. Even if you're not interested in clustering, this article gives you hands-on experience using Xen virtualization.
Linux Hardening Linux: a 10 step approach to a secure server
Post date: June 22, 2005, 06:06 Category: Security Views: 156
Tutorial quote: The Internet has become a far more dangerous place than it was 20 years ago. Nowadays, Operating System and application security is an integral part of a server configuration and, while firewalls are very important, they are not the panacea.

This list of steps is intended as a guideline with a practical approach. We’ll try to provide a complete picture without getting into unnecesary details. This list won’t replace a good book on secure systems administration, but it will be useful as a quick guide.

Before we get started it’s worth to mention that security is not a status: it’s just a process. The correct initial setup of the server only provides a good start and helps you get half the way through. But you actually need to walk the other half of the road, by providing proper security vigilance, monitoring and updating.
Unix+clones Execute Commands on Multiple Linux or UNIX Servers part II
Post date: December 28, 2005, 05:12 Category: System Views: 51
Tutorial quote: I have already covered how to execute commands on multiple Linux or UNIX servers via shell script. The disadvantage of script is commands do not run in parallel on all servers. However, several tools exist to automate this procedure in parallel. With the help of tool called tentakel, you run distributed command execution. It is a program for executing the same command on many hosts in parallel using ssh (it supports other methods too). Main advantage is you can create several sets of servers according requirements. For example webserver group, mail server group, home servers group etc. The command is executed in parallel on all servers in this group (time saving). By default, every result is printed to stdout (screen). The output format can be defined for each group.
Unix+clones Get More Out of Your Pipe with Apache and mod_gzip
Post date: April 14, 2005, 09:04 Category: Network Views: 41
Tutorial quote: Some Web sites seem like they are designed to annoy and alienate visitors. Teeny tiny fixed fonts, weirdo fixed page widths, ad servers on Mars, and the content won't load until the ads do, and all kinds of dynamic jiggery-pokery that does everything but quickly deliver a nice, readable page.

Webmasters who are serious about running high-performance Web servers, and who want pleased and delighted visitors, have a great tool in Apache 1.3's mod_gzip. mod_gzip compresses pages on the fly, reducing their size considerably. Depending on the types of files served, you'll see size reductions ranging from 20%- 80%, and a nice increase in server efficiency. Nothing is needed on the client side, except sane modern Web browsers like Mozilla, Firefox, Opera, Galeon, and Konqueror. Mozilla, Firefox, and Opera are nice cross-platform browsers with all kinds of neat features, so don't be afraid to standardize on one of them.
Linux Benchmarking Filesystems Part II
Post date: January 6, 2006, 17:01 Category: Benchmarks Views: 100
Tutorial quote: After the last article was published, I have received more than a dozen requests for a second filesystem benchmark using the 2.6 kernel. Since that time, I have converted entirely to XFS for every Linux machine I use, so I may be a bit bias regarding the XFS filesystem. I tried to keep the hardware roughly the same. Instead of a Western Digital 250GB and Promise ATA/100 controller, I am now am using a Seagate 400GB and Maxtor ATA/133 Promise controller. The physical machine remains the same, there is an additional 664MB of swap and I am now running Debian Etch. In the previous article, I was running Slackware 9.1 with custom compiled filesystem utilities. I've added a small section in the beginning that shows the filesystem creation and mount time, I've also added a graph showing these new benchmarks. After the first round of benchmarks, I received a sleuth of e-mails asking for the raw numbers. The numbers are now included in tables at the end of this e-mail for both the last and current set of benchmarks.
Yellow+Dog Installing Linux on the Mac mini
Post date: May 11, 2005, 08:05 Category: Installing Views: 112
Tutorial quote: The Mac mini is an ideal low-cost, high-performance PowerPC development platform for numerous applications. Learn how to install and configure Linux on the mini. Future articles will add the software required to make it into a stand-alone multimedia appliance.

This short series of articles shows you how to take a conveniently inexpensive, high-end PowerPC® platform (specifically, an Apple Mac mini) and build it into a home multimedia appliance using Linux™. At the end of the series, you'll have a stand-alone device that can play slide shows of images, audio, and movies, and that is controlled and administered from another machine using a standard Web browser.

The PowerPC platform is very well-suited to this type of multimedia application, and the G4 with AltiVec used in the Mac mini is an exceptionally powerful and flexible choice. This first article introduces you to the hardware's capabilities and walks you through installing and configuring Yellow Dog Linux so you can delve into some application code in the next article.
Linux Creating Really Teensy ELF Executables for Linux
Post date: April 12, 2005, 14:04 Category: Miscellaneous Views: 34
Tutorial quote: If you're a programmer who's become fed up with software bloat, then may you find herein the perfect antidote.

This document explores methods for squeezing excess bytes out of simple programs. (Of course, the more practical purpose of this document is to describe a few of the inner workings of the ELF file format and the Linux operating system. But hopefully you can also learn something about how to make really teensy ELF executables in the process.)

Please note that the information and examples given here are, for the most part, specific to ELF executables on a Linux platform running under an Intel-386 architecture. I imagine that a good bit of the information is applicable to other ELF-based Unices, but my experiences with such are too limited for me to say with certainty.

The assembly code that appears in this document is written for use with Nasm. (Besides being more appropriate for our needs, Nasm's syntax beats the hell out of AT&T syntax for anyone who learned x86 assembly language before learning to use Gas.) Nasm is freely available and extremely portable; see http://nasm.sourceforge.net/.

Please also note that if you aren't a little bit familiar with assembly code, you may find parts of this document sort of hard to follow.
Linux Three tools to help you configure iptables
Post date: May 25, 2005, 10:05 Category: Network Views: 90
Tutorial quote: Every user whose client connects to the Internet should configure his firewall immediately after installation. Some Linux distributions include firewall configuration as a part of installation, often offering a set of defaults configurations to choose from. However, to ensure that your machine presents the minimum "attack surface" (a measure of the number of vulnerable ports, user accounts, and sockets exposed to attack) to the predatory inhabitants of the Internet, you may need to do some manual configuration of your firewall. Here are three tools that can help.
The Linux kernel (version 2.4 onwards) contains a framework for packet filtering and firewalling using netfilter and iptables. Netfilter is a set of hooks inside the Linux kernel that allows kernel modules to register callback functions with the network stack. Iptables is a generic table structure for the definition of rulesets. Each rule within an IP table consists of a number of classifiers (iptables matches) and one connected action (iptables target). Iptables has extensive documentation that can be accessed online or by typing man iptables at the command line. Yet despite the depth of the documentation available for iptables, its complexity can be baffling.
Linux Linux Web Filtering in 7 steps
Post date: April 12, 2005, 14:04 Category: Network Views: 423
Tutorial quote: How to install a transparent Squid proxy server with real-time HTTP virus scanning on Mandrake 10.0 using DansGuardian and ClamAV?

People quickly and easily access volumes of research on the Internet and correspond with a mouse click. For more and more companies, content filtering is part of the large battle to combat all kinds of online threats, including hackers, worms and viruses. Linux content filtering allows administrators to configure and manage Internet access across the entire network and to block unwanted Web content like pornography, shopping Web sites, games and gambling.

This guide contains all the necessary information for installing and understanding the architectural layout of the implementation. It was written with the assumption that you understand how to install programs and have a basic understanding of Linux Mandrake. This includes installing Linux Mandrake and RPM packages, editing files, making directories, compiling software and understanding general UNIX commands. This guide doesn’t explain how to use or configure Squid, DansGuardian and ClamAV but information on where to obtain this information can be found in the “Additional information” section.