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Traversing Red Hat Enterprise Linux 5 on System p
So you've been the AIX guru on your team for years now and your bosses have determined that they want to try Linux on System p. You can fight the change, or you can embrace it and learn Linux, if not learn to love it. The purpose of this article is to introduce Linux to AIX administrators. It will show you what you need to know to make the transition to Linux simpler. It will also show you the equivalent commands to perform specific tasks and also discusses process management, filesystem management, how to peruse systems information, install packages, and other important bits of information that you as the systems administrator will need to know. While you will not become an expert at Linux from this article, this should give you a good head start in what you need to know.
  Articles   22 Jul 2008  
 
Running Informix Dynamic Server on Linux in Xen hypervisor
Can Informix Dynamic Server (IDS) run on Linux in Xen hypervisor virtual machines (VM)? Is all OS-specific functionality of IDS usable in a Xen VM? This article is a detailed summary of first experiences with running IDS for Linux in a Xen managed virtual machine. In this article, learn more about the benefits of Xen hypervisor and see how it works. Follow step-by-step guidelines to set up an actual test system, including the Xen virtualization layer. Finally, learn about the results of tests that the authors ran on their IDS environments.
  Articles   17 Jul 2008  
 
Anatomy of Linux loadable kernel modules
Linux loadable kernel modules, introduced in version 1.2 of the kernel, are one of the most important innovations in the Linux kernel. They provide a kernel that is both scalable and dynamic. Discover the ideas behind loadable modules, and learn how these independent objects dynamically become part of the Linux kernel.
  Articles   16 Jul 2008  
 
Integrate encryption into Google Calendar with Firefox extensions
Today's Web applications provide many benefits for online storage, access, and collaboration. Although some applications offer encryption of user data, most do not. This article provides tools and code needed to add basic encryption support for user data in one of the most popular online calendar applications. Building on the incredible flexibility of Firefox extensions and the Gnu Privacy Guard, this article shows you how to store only encrypted event descriptions in Google's Calendar application, while displaying a plain text version to anyone with the appropriate decryption keys.
  Articles   15 Jul 2008  
 
Automate backups on Linux
The loss of critical data can prove devastating. Still, millions of professionals ignore backing up their data. While individual reasons vary, one of the most common explanations is that performing routine backups can be a real chore. Because machines excel at mundane and repetitive tasks, the key to reducing the inherent drudgery and the natural human tendency for procrastination, is to automate the backup process.
  Articles   03 Jul 2008  
 
Common threads: Awk by example, Part 1
Awk is a very nice language with a very strange name. In this first article of a three-part series, Daniel Robbins will quickly get your awk programming skills up to speed. As the series progresses, more advanced topics will be covered, culminating with an advanced real-world awk application demo.
  Articles   03 Jul 2008  
 
Migrate device control applications from Windows to Linux
Ease the pain of migrating device control applications from Microsoft Windows to Linux by understanding how device control works in both operating systems. The authors outline these differences and give you a C/C++ migration sample.
  Articles   24 Jun 2008  
 
Core partners, Part 4: Managing the PlayStation 3 Wi-Fi network
Terra Soft Solutions IT Manager Aaron Johnson shows you, step-by-step, how to configure and encrypt the built-in Wi-Fi network that comes with the Cell Broadband Engine(TM)-based Sony PlayStation 3. And, as a little bonus, get 16 quick steps that explain how to switch from a wireless network back to a wired network on the PS3.
  Articles   17 Jun 2008  
 
Anatomy of Linux journaling file systems
In recent history, journaling file systems were viewed as an oddity and thought of primarily in terms of research. But today, a journaling file system (ext3) is the default in Linux. Discover the ideas behind journaling file systems, and learn how they provide better integrity in the face of a power failure or system crash. Learn about the various journaling file systems in use today, and peek into the next generation of journaling file systems.
  Articles   04 Jun 2008  
 
Porting applications to Linux for System z
Server consolidation based on Linux for IBM System z offers advantages, but moving existing applications requires some specialized knowledge. In this article, get general advice on how to organize your porting project, including technical details on mainframe virtualization, byte-ordering, and address calculation specific to System z. This article also covers how development tools (compiler, linker, debugger) are supported on System z, and introduces IBM's free-of-charge Migration Kit for Solaris OS to Linux.
  Articles   28 May 2008  
 
Anatomy of Linux flash file systems
You've probably heard of Journaling Flash File System (JFFS) and Yet Another Flash File System (YAFFS), but do you know what it means to have a file system that assumes an underlying flash device? This article introduces you to flash file systems for Linux, and explores how they care for their underlying consumable devices (flash parts) through wear leveling, and identifies the various flash file systems available along with their fundamental designs.
  Articles   20 May 2008  
 
Manage widget geometry in PyGTK
Several container widgets exist in GTK+, and with the toolkit's API, you can create user-defined containers. This API is also exposed to PyGTK. In this article, learn how to create a "weighted-table" container in PyGTK. The implementation introduces you to the basic model of GTK+ geometry management and gives you a feel for what to consider and expect when implementing container widgets.
  Articles   20 May 2008  
 
Install Java 5 EE and IBM WebSphere Application Server Community Edition V2 on openSUSE, Part 1
This demo shows how to extract and install the IBM Java Platform, Enterprise Edition 5 (Java EE 5) SDK that is bundled with the IBM WebSphere Application Server Community Edition application on the openSUSE Linux platform. It also highlights the key parameters required to configure a Java Virtual Machine (JVM) in the .bash_profile as well as point out how the default JVM and WebSphere Application Server Community Edition installation enables access for multiple users. Part 2 of this demo shows how to install WebSphere Application Server Community Edition V2 on openSUSE Linux.
  Demos   08 May 2008  
 
Install Java 5 EE and IBM WebSphere Application Server Community Edition V2 on openSUSE, Part 2
Part 1 of this demo showed how to extract and install the IBM Java Platform, Enterprise Edition 5 (Java EE 5) SDK that is bundled with IBM WebSphere Application Server Community Edition. This demo shows how to install WebSphere Application Server Community Edition V2 on the openSUSE Linux platform.
  Demos   08 May 2008  
 
Install IBM WebSphere Application Server Community Edition V1.x on Linux
Learn how to install the IBM WebSphere Application Server Community Edition V1.x in a Linux x86 environment for use by multiple users. IBM WebSphere Application Server Community Edition is an open community application server based on the Apache Geronimo open source application server. Download WebSphere Application Server Community Edition for the Linux x86 platform or a Windows environment from developerWorks.
  Demos   08 May 2008  
 
Explore the IBM WebSphere Application Server Community Edition Admin Console on Linux
Explore some of the features and functions of IBM WebSphere Application Server Community Edition Administrative Console in a Linux x86 environment for use by multiple users. WebSphere Application Server Community Edition is an open community application server based on the Apache Geronimo open source application server. Download WebSphere Application Server Community Edition for the Linux x86 platform or a Windows environment from developerWorks.
  Demos   08 May 2008  
 
IBM open collaboration client solution: An overview
Learn what's involved when introducing a Linux® client pilot in your organization, including planning for business and IT requirements, architecture decisions, risks, and understanding how IBM's open collaboration client is used to implement this desktop of the future, today.
  Articles   07 May 2008  
 
IBM open collaboration client solution: Organizational planning and user segmentation for desktop migration
Learn the steps involved in migrating your environment to that of a Linux® client, including organizational planning and user segmentation. Based on customer experiences, this article offers a comprehensive guide to planning and executing your migration while minimizing disruption to your users.
  Articles   07 May 2008  
 
IBM open collaboration client solution: Technical planning
Learn the steps involved in migrating your environment to that of a Linux client, including technical planning. Based on customer experiences, this article offers a comprehensive guide to planning and executing your migration while minimizing disruption to your users.
  Articles   07 May 2008  
 
Install and boot Linux on BladeCenter S from an attached disk
The IBM BladeCenter S chassis is the first IBM BladeCenter to integrate server and storage. In this article, learn how to install SUSE Linux 10 on the blade's attached disk and then how to boot the blade server from the attached disk. The article also covers how to check the storage and blade status, how to map the disk to the blade, how to configure an SAS disk as the boot media, how to install the operating system on the attached disk, and how to handle the most common installation error.
  Articles   06 May 2008  
 
Migrating to ext4
Ext4 is the latest in a long line of Linux file systems, and it's likely to be as important and popular as its predecessors. As a Linux system administrator, you should be aware of the advantages, disadvantages, and basic steps for migrating to ext4. This article explains when to adopt ext4, how to adapt traditional file system maintenance tool usage to ext4, and how to get the most out of the file system.
  Articles   30 Apr 2008  
 
Anatomy of Security-Enhanced Linux (SELinux)
Linux has been described as one of the most secure operating systems available, but the National Security Agency (NSA) has taken Linux to the next level with the introduction of Security-Enhanced Linux (SELinux). SELinux takes the existing GNU/Linux operating system and extends it with kernel and user-space modifications to make it bullet-proof. If you're running a 2.6 kernel today, you might be surprised to know that you're using SELinux right now! This article explores the ideas behind SELinux and how it's implemented.
  Articles   29 Apr 2008  
 
IBM open collaboration client solution: Migrating applications to the Linux desktop
Have you wanted to port your infrastructure and business line applications to a Linux desktop environment, but been deterred by the need to access critical Microsoft Windows or legacy applications? Finding a way to support these critical business line applications is crucial when considering the move to Linux. This article highlights the various tools that let you access these applications from Linux desktops.
  Articles   29 Apr 2008  
 
Install Apache Geronimo v1.x on Linux
See how easy it is to install Apache Geronimo in a Linux environment. This demo shows how to install Apache Geronimo v1.x, an open source application server available from the Apache Software Foundation, in a Linux x86 environment for use by multiple developers.
  Demos   16 Apr 2008  
 
Configuring WebSphere Message Broker V6.1 on z/Linux
You have a number of options when configuring WebSphere Message Broker on z/Linux, including support for 64-bit applications in order to access DB2 and WebSphere MQ data on z/OS, use of IFL processors to lower the cost of ownership for WebSphere Message Broker, and use of HiperSockets for fast communication using TCP/IP-based protocols. This article has the details.
  Articles   16 Apr 2008  
 
Cell/B.E. SDK 3.0 tools, Part 1: Using performance tools
This introductory tutorial, designed as a companion for the IBM SDK for Multicore Acceleration, Version 3.0 (otherwise known as the Cell Broadband Engine(R) SDK), teaches you how to use five performance tools that reside in the SDK 3.0: OProfile, Cell Performance Counter, Performance Debugging Tool, the PDT Trace Reader, and FDPR-Pro. The Visual Performance Analyzer, available separately, is also highlighted.
  Tutorial   15 Apr 2008  
 
LPI exam 301 prep, Topic 306: Capacity planning
In this tutorial, Sean Walberg helps you prepare to take the Linux Professional Institute Senior Level Linux Professional (LPIC-3) exam. In this last in a series of six tutorials, Sean walks you through monitoring your system resources, troubleshooting resource problems, and analyzing system capacity.
  Tutorial   15 Apr 2008  
 
Anatomy of real-time Linux architectures
It's not that Linux isn't fast or efficient, but in some cases fast just isn't good enough. What's needed instead is the ability to deterministically meet scheduling deadlines with specific tolerances. Discover the various real-time Linux alternatives and how they achieve real time -- from the early architectures that mimic virtualization solutions to the options available today in the standard 2.6 kernel.
  Articles   15 Apr 2008  
 
LPI exam 301 prep, Topic 305: Integration and migration
In this tutorial, Sean Walberg helps you prepare to take the Linux Professional Institute Senior Level Linux Professional (LPIC-3) exam. In this fifth in a series of six tutorials, Sean walks you through integrating LDAP with your system's logins and applications. He also details the procedure to integrate your server into a foreign Microsoft Active Directory.
  Tutorial   08 Apr 2008  
 
Linux development on the PlayStation 3, Part 3: Slimming down X11 with tiny tools
The Sony PlayStation 3 (PS3) runs Linux, but getting it to run well requires some tweaking. In the third and final article of this series on PS3 Linux, Peter Seebach talks about ways to get X11 slimmed down to fit on a smaller memory budget.
  Articles   08 Apr 2008  
 
Discover tput
One of the strongest assets UNIX has is the ability to make shell scripts to ease users' lives. These scripts can range from simple one-liners to several thousand lines. Many times, shell scripts evolve into menu-based scripts, and the scripter wants to display more to users than simply scrolling text. Other times, a simple line or two of output are displayed to users, and the shell scripter wants to put emphasis on a warning message.
  Articles   01 Apr 2008  
 
Linux development on the PlayStation 3, Part 2: Working with memory
The Sony PlayStation 3 (PS3) runs Linux, but getting it to run well requires some tweaking. In this article, the second in a series, Peter Seebach takes a look at where all the memory goes and how to reclaim it.
  Articles   31 Mar 2008  
 
Performance tradeoffs of TCP Selective Acknowledgment
Selective acknowledgment (SACK) is an optional feature of TCP that is necessary to effectively use all of the available bandwidth of some networks. While SACK is good for throughput, processing this type of acknowledgment has proven to be CPU intensive for the TCP sender. This weakness can be exploited by a malicious peer even under commodity network conditions. This article presents experimental measurements that characterize the extent of the problem within the Linux TCP stack. SACK is enabled by default on most distributions.
  Articles   31 Mar 2008  
 
LPI exam 301 prep, Topic 304: Usage
In this tutorial, Sean Walberg helps you prepare to take the Linux Professional Institute Senior Level Linux Professional (LPIC-3) exam. In this fourth in a series of six tutorials, Sean walks you through searching your LDAP tree and using the command-line tools. You'll also learn how to set up Microsoft Outlook to query your LDAP tree.
  Tutorial   25 Mar 2008  
 
Monitor mainframe sessions remotely
Users access z/OS mainframes using a 3270 terminal emulator. In this article, learn how to build a simple shell script for UNIX or Linux that gives you a second terminal emulator to view everything a mainframe user is doing in real time.
  Articles   19 Mar 2008  
 
Linux development on the PlayStation 3, Part 1: More than a toy
The Sony PlayStation 3 (PS3) runs Linux, but getting it to run well requires some tweaking. In this article, first in a series, Peter Seebach introduces the features and benefits of PS3 Linux, and explains some of the issues that might benefit from a bit of tweaking.
  Articles   18 Mar 2008  
 
LPI exam 301 prep, Topic 303: Configuration
In this tutorial, Sean Walberg helps you prepare to take the Linux Professional Institute Senior Level Linux Professional (LPIC-3) exam. In this third in a series of six tutorials, Sean walks you through configuring a Lightweight Directory Access Protocol (LDAP) server, including access control, security, and performance. By the end of this tutorial, you'll know about LDAP server configuration.
  Tutorial   04 Mar 2008  
 
Changing UIDs and GIDs
It's important to know what happens to file ownership in AIX once you make a UID or GID change. If you don't understand the results of altering a UID or GID, you could cause serious issues to your server and environment.
  Articles   04 Mar 2008  
 
Multipath storage with Xen and DS4800
As the Xen open source hypervisor gains traction in many enterprises for production deployment, you may need to provide fully redundant storage to the Xen environment from the host adapter all the way down to the hard drives. In this article, learn how to use Red Hat Enterprise Linux 5.1 to set up Xen and multipath storage access to the IBM System Storage DS4800.
  Articles   04 Mar 2008  
 
Desktop development for the OLPC laptop
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). This article is excerpted from the developerWorks tutorial "Application development for the OLPC laptop," which takes a look at the Sugar APIs and shows how to develop and debug a graphical activity in Sugar using Python.
  Articles   26 Feb 2008  
 
Improve security with polyinstantiation
If you're concerned about protecting world-writeable shared directories such as /tmp or /var/tmp from abuse, a Linux Pluggable Authentication Module (PAM) can help you. The pam_namespace module creates a separate namespace for users on your system when they login. This separation is enforced by the Linux operating system so that users are protected from several types of security attacks. This article for Linux system administrators lays out the steps to enable namespaces with PAM.
  Articles   26 Feb 2008  
 
Systems Administration Toolkit: Log file basics
A typical UNIX or Linux machine creates many log files during the course of its operation. Some of these contain useful information; others can be used to help you with capacity and resource planning. This article looks at the fundamental information recorded within the different log files, their location, and how that information can be used to your benefit to work out what is going on within your system.
  Articles   26 Feb 2008  
 
Building your own memory manager for C/C++ projects
Performance optimization of code is serious business. It's fairly common to see a piece of functionally correct software written in C or C++ that takes way too much memory, time, or, in the worst case, both. As a developer, one of the most powerful tools that C/C++ arms you with to improve processing time and prevent memory corruption is the control over how memory is allocated or deallocated in your code. This tutorial demystifies memory management concepts by telling you how to create your very own memory manager for specific situations.
  Tutorial   19 Feb 2008  
 
Role-based access control in SELinux
Role-based access control (RBAC) is a general security model that simplifies administration by assigning roles to users and then assigning permissions to those roles. RBAC in Security-Enhanced Linux (SELinux) acts as a layer of abstraction between the user and the underlying type-enforcement (TE) model, which provides highly granular access control but is not geared for ease of management. Learn how the three pieces of an SELinux context (policy, kernel, and userspace) work together to enforce the RBAC and tie Linux users into the TE policy.
  Articles   13 Feb 2008  
 
SNMP-based monitoring for GPFS clusters
New in version 3.2, IBM General Parallel File System (GPFS) on Linux provides Simple Network Management Protocol (SNMP) services that let administrators collect SNMP data about the health of a GPFS cluster so that problems such as disk failure can be quickly identified. The system lets a collector node gather the trap information, which an administrator can then monitor and analyze remotely on a separate management node. This article provides a method for basic verification of SNMP in a GPFS cluster.
  Articles   29 Jan 2008  
 
Explore Ubuntu Mobile and Embedded
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.
  Tutorial   15 Jan 2008  
 
Cell/B.E. container virtualization, Part 2: Implementation issues
This three-part series illustrates a hardware-resource-focused form of software virtualization known as container virtualization (or operating system virtualization), demonstrated through the open source project OpenVZ. The series provides a comprehensive overview of all the components and techniques needed to virtualize the Cell/B.E. processor with software methods. This second article of the series details the implementation of dedicated virtualization and partitioning that was described in Part 1 of the series.
  Articles   08 Jan 2008  
 
Multiprocessing with the Completely Fair Scheduler
The Linux 2.6.23 kernel comes with a modular scheduler core and a Completely Fair Scheduler (CFS), which is implemented as a scheduling module. In this article, get acquainted with the major features of the CFS, see how it works, and look ahead to some of the expected changes for the 2.6.24 release.
  Articles   08 Jan 2008  
 
Networking scalability on high-performance servers
The proliferation of high-performance scalable servers has added a new level of complexity to networking and system performance. In this article, learn how to optimize your multi-node, high-performance Linux system as it uses system board gigabit Ethernet adapters from 1 to 4 nodes. Take a look at problematic networking scalability situations and get tips on how to avoid the pitfalls.
  Articles   01 Jan 2008  
 
Application development for the OLPC laptop
The XO laptop (of the One-Laptop-Per-Child initiative) is an inexpensive laptop project intended to help educate children around the world. The XO 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.
  Tutorial   18 Dec 2007  
 
Cell/B.E. container virtualization, Part 1: Concepts, architectures, and tools
This three-part series illustrates a hardware-resource-focused form of software virtualization known as container virtualization (or operating system virtualization), demonstrated through the open source project OpenVZ. The series provides a comprehensive overview of all the components and techniques needed to virtualize the Cell/B.E. processor with software methods. This first article of the series discusses the basic concepts involved, illustrates the salient points of the OpenVZ and Cell/B.E. architectures and how they work together, and describes some of the OpenVZ tools.
  Articles   11 Dec 2007  
 
LPI exam 301 prep, Topic 302: Installation and development
In this tutorial, Sean Walberg helps you prepare to take the Linux Professional Institute Senior Level Linux Professional (LPIC-3) exam. In this second in a series of six tutorials, Sean 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.
  Tutorial   04 Dec 2007  
 
Linux on board: Auto-uploading Nokia N800 photos
These three installments of Linux on board show you how to get started building applications for the Nokia N800 by way of a working example: using the camera feature to create a Webcam. In this third and final installment, write an automatic photo-uploading routine for the photos you've taken.
  Articles   04 Dec 2007  
 
Linux on board: Accessing the Nokia N800 camera
These three installments of Linux on board show you how to get started building applications by way of a working example: using the camera feature to create a Webcam. In this installment, walk through the start of building a camera application using gstreamer to access the Nokia N800 device's Webcam. (It's not as much work as you might think, especially since we borrow from an existing application.)
  Articles   27 Nov 2007  
 
Linux on board: Developing for the Nokia N800
Root around inside the heart of the Nokia N800 phone/Internet tablet/Webcam and take a closer look at the build environment, based on scratchbox.
  Articles   20 Nov 2007  
 
Anatomy of the Linux SCSI subsystem
The Small Computer Systems Interface (SCSI) is a collection of standards that define the interface and protocols for communicating with a large number of devices (predominantly storage related). Linux provides a SCSI subsystem to permit communication with these devices. Linux is a great example of a layered architecture that joins high-level drivers, such as disk or CD-ROM drivers, to a physical interface such as Fibre Channel or Serial Attached SCSI (SAS). This article introduces you to the Linux SCSI subsystem and discusses where this subsystem is going in the future.
  Articles   14 Nov 2007  
 
Software development for the OpenMoko Linux phone
The OpenMoko environment provides a completely free development environment for running application and system code on supported phone hardware, eliminating all dependency on proprietary code. This tutorial introduces the OpenEmbedded build environment used to create filesystem images for OpenMoko phones, such as the Neo 1973.
  Tutorial   13 Nov 2007  
 
Emacs editing environment, Part 7: Let Emacs help you out
Part 7 of this series shows you why Emacs is the self-documenting editor, and the many ways in which you can take advantage of the help and assistance offered in this editor. In this tutorial, learn about describing keystrokes, commands, and functions. You'll also read, browse, and search through a complete Emacs reference manual.
  Tutorial   13 Nov 2007  
 
Anatomy of Linux synchronization methods
In your Linux education, you may have learned about concurrency, critical sections, and locking, but how do you use these concepts within the kernel? This article reviews the locking mechanisms available within the 2.6 kernel, including atomic operators, spinlocks, reader/writer locks, and kernel semaphores. It also explores where each mechanism is most applicable for building safe and efficient kernel code.
  Articles   31 Oct 2007  
 
Anatomy of the Linux file system
When it comes to file systems, Linux is the Swiss Army knife of operating systems. Linux supports a large number of file systems, from journaling to clustering to cryptographic. Linux is a wonderful platform for using standard and more exotic file systems and also for developing file systems. This article explores the virtual file system (VFS) -- sometimes called the virtual filesystem switch -- in the Linux kernel and then reviews some of the major structures that tie file systems together.
  Articles   30 Oct 2007  
 
LPI exam 301 prep, Topic 301: Concepts, architecture, and design
In this tutorial, Sean Walberg helps you prepare to take the Linux Professional Institute Senior Level Linux Professional (LPIC-3) exam 301. In this first in a series of six tutorials, Sean introduces you to Lightweight Directory Access Protocol (LDAP) concepts, architecture, and design. By the end of this tutorial, you will know about LDAP concepts and architecture, directory design, and schemas.
  Tutorial   23 Oct 2007  
 
Linux assemblers: A comparison of GAS and NASM
This article explains some of the more important syntactic and semantic differences between two of the most popular assemblers for Linux, GNU Assembler (GAS) and Netwide Assembler (NASM), including differences in basic syntax, variables and memory access, macro handling, functions and external routines, stack handling, and techniques for easily repeating blocks of code.
  Articles   17 Oct 2007  
 
Minimize recoding impact, Part 2: Removing obstacles to speedy performance
The first article in the series describes how to do a basic port to the Cell Broadband Engine process. This second article goes further in hammering out the details, including removing limitations based on DMA-transfer size, partitioning the program across multiple SPEs, and improving the program's speed even more.
  Articles   16 Oct 2007  
 
POSIX file capabilities: Parceling the power of root
Linux has been using capabilities for years, but has recently acquired POSIX file capabilities. POSIX file capabilities split root user powers into smaller privileges, such as the ability to read files or to trace processes owned by another user. By assigning capabilities to a file, you can enable an unprivileged user to execute the file with those specified privileges. In this article, learn how to program using capabilities and how to switch on the ability of your system setuid root binaries to use file capabilities.
  Articles   16 Oct 2007  
 
PS3 fab-to-lab, Part 2: Generating and analyzing signals
How do you take the Cell Broadband Engine (Cell/B.E.) processor from an off-the-shelf Sony PLAYSTATION 3 (PS3) and use it to construct a piece of Linux(R)-based laboratory equipment (in essence, take the Cell/B.E. from fab to hab to lab)? In this series, Lewin Edwards shows you how to go from game console to simple audio-bandwidth spectrum analyzer and function generator. In this article, the author shows you how to build on the infrastructure from Part 1 to make the system into a fully operational, if primitive, spectrum analyzer.
  Articles   02 Oct 2007  
 
IBM Installation Toolkit: Loading Linux on POWER
The IBM Installation Toolkit for Linux on POWER simplifies the installation of Linux on virtualized and non-virtualized Power machines, gives you a bootable rescue DVD, and provides the software needed to fully exploit the Power platform. Learn to use the toolkit to install Red Hat Enterprise Linux and SUSE Linux Enterprise Server on IBM System p and System i5 machines.
  Articles   26 Sep 2007  
 
Metaclass programming in Python, Part 3
Too much cleverness in programming makes designs more complicated, code more fragile, learning curves steeper, and worst of all, it makes debugging harder. Michele and David feel, in part, responsible for some excesses of cleverness that followed the enthusiastic reception of their earlier articles on Python metaclasses. In this article, they attempt to make amends, by helping programmers eschew cleverness.
  Articles   25 Sep 2007  
 
System emulation with QEMU
QEMU is an open source emulator for complete PC systems. In addition to emulating a processor, QEMU permits emulation of all necessary subsystems, such as networking and video hardware. It also permits emulation of advanced concepts, such as symmetric multiprocessing systems (up to 255 CPUs) and other processor architectures, such as ARM or PowerPC. This article explores QEMU and its architecture and shows how to emulate a guest operating system on a Linux host.
  Articles   25 Sep 2007  
 
Logical volume management
Volume management is not new in the -ix world (UNIX, AIX, and so forth). And logical volume management (LVM) has been around since Linux kernel 2.4v1 and 2.6.9v2. This article reveals the most useful features of LVM2--a relatively new userspace toolset that provides logical volume management facilities--and suggests several ways to simplify your system administration tasks. Based on reader feedback, the author has updated Listings 10, 14, 15, and 16. -Ed.
  Articles   20 Sep 2007  
 
Applying mount namespaces
What if you could allow users to craft their own filesystem setup without being constrained by the sysadmin-dictated structure? Users could export part of their own filesystem tree and import other users' exported filesystem trees into their tree. This article provides a step-by-step guide for Linux system administrators to allow users to do just that with mount propagation.
  Articles   17 Sep 2007  
 
Cross-platform graphics with cairo
Built from the ground up to create identical output on both printer and screen -- all in a cross-platform way -- cairo is becoming a huge player in the Linux graphics space. Harness the same 2D power used by GNOME, GTK+, Pango, and many others.
  Articles   05 Sep 2007  
 
Minimize recoding impact, Part 1: How to make an SPE and existing code work together
Traditional porting requires identifying and abstracting out the architecture-dependent code: making code endian-independent, working through minor API differences, and including the appropriate header files and libraries. While this procedure works for getting code to run on the Cell Broadband Engine (Cell/B.E.) processor, to actually use the extra processing elements, you have to put in extra work, including reworking the code and rethinking the build process. In this series, learn to take advantage of the Synergistic Processor Elements (SPEs) in existing code and only make a minimal impact to the existing code and build process.
  Articles   04 Sep 2007  
 
Charming Python: Python elegance and warts, Part 2
In this series of two articles, David discusses the non-obvious features and misfeatures that have been added to the last several Python versions, with the goal of helping part-time Python programmers uncover the gems while avoiding the pitfalls. This installment adds attributes and methods, descriptors, and properties to the discussion.
  Articles   29 Aug 2007  
 
Set up a Web server cluster in 5 easy steps
Construct a highly available Apache Web server cluster that spans multiple physical or virtual Linux servers in 5 easy steps with Linux Virtual Server and Heartbeat v2.
  Articles   22 Aug 2007  
 
Linux tip: Controlling the duration of scheduled jobs
Say you need to debug a pesky problem by running some traces for 30 minutes at midnight, or you would just like to use your Linux system as an alarm clock. This tip helps you stop jobs, such as those started with the cron and at capabilities, after the jobs have run for a certain time, or when some other criteria are met.
  Tips   31 Jul 2007  
 
Use gperf for efficient C/C++ command line processing
The GNU tool gperf is a "perfect" hash function that, for a given set of user-provided strings, generates C/C++ code for a hash table, a hash function, and a lookup function. Learn how to use gperf for effective command-line processing in your C/C++ code.
  Articles   25 Jul 2007  
 
Linux project publications: Security
The publications on this page represent contributions by members of the IBM Linux Technology Center to the development community on the topic of Linux security.
  Articles   24 Jul 2007  
 
Industrial-strength Linux lockdown, Part 2: Executing only signed binaries
For technical and non-technical users alike, maintaining a large installed base of Linux machines can be a harrowing experience for an administrator. Technical users take advantage of Linux's extreme configurability to change everything to their liking, while non-technical users running amok within their own file systems. This tutorial is the second in a two-part series on locking your Linux machines down to streamline the associated support and administration processes. In this tutorial, you learn how to configure the Linux kernel to execute only signed binaries.
  Tutorial   18 Jul 2007  
 
Linux tip: Job scheduling with cron and at
You need to run a job at midnight when system usage is low, or you need to run jobs daily or weekly, but you would rather be sleeping, or enjoying life in some other way. Other good reasons for scheduling jobs include letting routine tasks happen automatically, or ensuring tasks are handled the same way every time. This tip helps you use the cron and at capabilities to schedule jobs periodically or at a single future time.
  Tips   18 Jul 2007  
 
Changes in libspe: How libspe2 affects Cell Broadband Engine programming
The standard library that Power Processor Element (PPE) programs use to access and manage Synergistic Processor Elements (SPEs), called libspe, has undergone a major revision. The Cell Broadband Engine (Cell/B.E.) SDK 2.1 officially changes the library interface from libspe1 to libspe2. In this article, Jonathan Bartlett introduces the libspe2 concepts and shows how to do basic SPE process management and communication with libspe2.
  Articles   17 Jul 2007  
 
LPI exam 102 prep, Topic 111: Administrative tasks
In this tutorial, Ian Shields continues preparing you to take the Linux Professional Institute Junior Level Administration (LPIC-1) Exam 102. In this sixth in a series of nine tutorials, Ian introduces you to administrative tasks. By the end of this tutorial, you will know how to manage users and groups, set user profiles and environments, use log files, schedule jobs, back up your data, and maintain the system time.
  Tutorial   10 Jul 2007  
 
Lightweight Web servers
Recent years have enjoyed a florescence of interesting implementations of Web servers, including lighttpd, litespeed, and mongrel, among others. These Web servers boast different combinations of performance, ease of administration, portability, security, and related values. The following engineering study surveys the field of lightweight Web servers to help you find one likely to meet the technical requirements of your next project.
  Articles   10 Jul 2007  
 
The distro jungle
People who are new to Linux are often confused by the large number of distributions to choose from. The good news is that you can safely ignore most of them. This article helps you choose a distribution for getting started with your Linux exploration -- and helps you understand just what it is you've just chosen.
  Articles   28 Jun 2007  
 
DB2 and open source, Part 2: Put yourself on the map with Google Maps API Version 2, DB2/Informix, PHP, and JMeter on Linux
Google's new Maps API version 2 allows for more advanced mashup applications. In this article, you'll move on from the basic mashup development explained in part 1, and see how to use DB2's REC2XML function, eliminating lines of code from the PHP scripts. You'll learn how to implement this solution on either DB2 or Informix Dynamic Server.
  Articles   28 Jun 2007  
 
Anatomy of the Linux networking stack
One of the greatest features of the Linux operating system is its networking stack. It was initially a derivative of the BSD stack and is well organized with a clean set of interfaces. Its interfaces range from the protocol agnostics, such as the common sockets layer interface or the device layer, to the specific interfaces of the individual networking protocols. This article explores the structure of the Linux networking stack from the perspective of its layers and also examines some of its major structures.
  Articles   27 Jun 2007  
 
Installing a large Linux cluster, Part 4: Node installation and GPFS cluster configuration
Create a working Linux(R) cluster from many separate pieces of hardware and software, including System x(TM) and IBM TotalStorage(R) systems. Part 4 provides the second half of the instructions you need to set up the storage backend, including installing General Parallel File System (GPFS) code on each node and configuring Qlogic adapters for storage nodes. Finally, this article takes you through the steps to create a GPFS cluster.
  Articles   14 Jun 2007  
 
Turbocharge Ruby on Rails with ActiveScaffold
Save time and headaches, and create a more easily maintainable set of pages, with the Ruby on Rails ActiveScaffold plugin. ActiveScaffold handles all your CRUD (create, read, update, delete) user interface needs, leaving you more time to focus on more challenging (and interesting!) problems.
  Articles   08 Jun 2007  
 
Tuning LAMP systems, Part 3: Tuning your MySQL server
Applications using the LAMP (Linux, Apache, MySQL, PHP/Perl) architecture are constantly being developed and deployed. But often the server administrator has little control over the application itself because it's written by someone else. This series of three articles discusses many of the server configuration items that can make or break an application's performance. This third article, the last in the series, focuses on tuning the database layer for maximum efficiency.
  Articles   07 Jun 2007  
 
Anatomy of the Linux kernel
The Linux kernel is the core of a large and complex operating system, and while it's huge, it is well organized in terms of subsystems and layers. In this article, you explore the general structure of the Linux kernel and get to know its major subsystems and core interfaces. Where possible, you get links to other IBM articles to help you dig deeper.
  Articles   06 Jun 2007  
 
Six ways to write more comprehensible code
As a developer, time is your most valuable resource. These six tips on how to write maintainable code are guaranteed to save you time and frustration: one minute spent writing comments can save you an hour of anguish.
  Articles   29 May 2007  
 
Industrial-strength Linux lockdown, Part 1: Removing the shell
For technical and non-technical users alike, maintaining a large installed base of Linux machines can be a harrowing experience for an administrator. Technical users take advantage of Linux's extreme configurability to change everything to their liking, while non-technical users running amok within their own file systems. This tutorial is the first in a two-part series that shows you how and why to lock those machines down to streamline the associated support and administration processes. In this tutorial, you learn how to remove the interpreters from the installation base system.
  Tutorial   23 May 2007  
 
Deploy Red Hat across multiple computers using Tivoli Provisioning Manager for OS Deployment
Any time you have employees, overhead costs are going to be substantial, especially when it comes to new hires. Of the many things new employees need, setting up their computer and its operating system, and installing and configuring appropriate applications is one of the most time-consuming. Tivoli Provisioning Manager for OS Deployment greatly reduces this overhead by allowing you to create and manage deployable images and any associated software packages efficiently through a Web interface. This tutorial shows you how to use Tivoli Provisioning Manager for OS Deployment to create installation images and manage packages for an actual deployment of RedHat Enterprise Linux.
  Tutorial   22 May 2007  
 
Linux tip: Bash parameters and parameter expansions
Do you sometimes wonder how to use parameters with your scripts, and how to pass them to internal functions or other scripts? Do you need to do simple validity tests on parameters or options, or perform simple extraction and replacement operations on the parameter strings? This tip helps you with parameter use and the various parameter expansions available in the bash shell.
  Articles   16 May 2007  
 
PS3 fab-to-lab, Part 1: Build Linux lab equipment from a Sony PLAYSTATION 3
How do you take the Cell Broadband Engine (Cell/B.E.) processor from an off-the-shelf Sony PLAYSTATION 3 (PS3) and use it to construct a piece of Linux-based laboratory equipment (in essence, taking the Cell/B.E. from fab to hab to lab)? In this series, Lewin Edwards shows you how to go from game console to simple audio-bandwidth spectrum analyzer and function generator. First up, uncover the design intent of the project and then make a close inspection of the details of the user interface implementation as you start a journey to generate and analyze signals on the Cell/B.E. processor.
  Articles   15 May 2007  
 
Anatomy of the Linux slab allocator
Good operating system performance depends in part on the operating system's ability to efficiently manage resources. In the old days, heap memory managers were the norm, but performance suffered due to fragmentation and the need for memory reclamation. Today, the Linux kernel uses a method that originated in Solaris but has been used in embedded systems for quite some time, allocating memory as objects based on their size. This article explores the ideas behind the slab allocator and examines its interfaces and their use.
  Articles   15 May 2007  
 
Setting up a multicluster environment using General Parallel File System
Learn how to construct and deconstruct a simple multicluster of System x(TM)and System p(TM) computers using the General Parallel File System (GPFS). You can remotely add an existing GPFS cluster to another cluster. See how to mount a file system from the remote cluster using the GPFS secure communication protocol.
  Articles   11 May 2007  
 
Installing a large Linux cluster, Part 3: Storage and shared file systems
Create a working Linux(R) cluster from many separate pieces of hardware and software, including System x(TM) and IBM TotalStorage(R) systems. Part 3 provides the first half of the instructions you need to set up the storage backend, including details on storage architecture, needed hardware, and the Storage Area Network.
  Articles   04 May 2007  
 
Jump start WebSphere MQ development on Linux
This article shows you how to get started installing and configuring WebSphere MQ on Linux and developing Java applications for the MQ environment, using sample applications for sending messages to and receiving messages from a queue.
  Articles   02 May 2007  
 
Linux system auditing by example
Think you have a secure Linux system? Following best practices during installation and setup is a must, but if you haven't set up regular system auditing, you're missing half the picture. This article discusses some existing tools and offers a couple of sample scripts to automate the process in a real-world environment.
  Articles   30 Apr 2007  
 
Second Life client, Part 2: Digging into the documentation
The developer documentation in the Second Life client takes the form of a wiki. In Part 2 of our ongoing exploration of the Second Life software, take a look at that documentation, and use it to jump-start some modifications to the client.
  Articles   30 Apr 2007  
 
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