The Linux Professional Institute(LPI)
 Certification for Linux

Bochs, like QEMU, is a portable emulator that provides a virtualization environment in which to run an operating system using an emulated platform in the context of another operating system. Bochs isn't a hypervisor but rather a PC-compatible emulator useful for legacy software. Learn about platform emulation using Bochs and its approach to hardware emulation.

Although ZFS exists in an operating system whose future is at risk, it is easily one of the most advanced, feature-rich file systems in existence. It incorporates variable block sizes, compression, encryption, de-duplication, snapshots, clones, and (as the name implies) support for massive capacities. Get to know the concepts behind ZFS and learn how you can use ZFS today on Linux using Filesystem in Userspace (FUSE).

Learn to shut down or reboot your Linux system, warn users that the system is going down, and switch to a more or less restrictive runlevel. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to learn about shutting down, rebooting, and changing runlevels.

BeagleBoard.org recently introduced BeagleBoard revision xM, a new edition of the highly successful open-hardware BeagleBoard currently at revision C. This article describes the necessary environment and steps for booting Linux on the BeagleBoard-xM with Angstrom Linux, Android, and Ubuntu.

Learn to manage file ownership and permissions on your Linux filesystems. Learn about access modes such as suid, sgid, and the sticky bit and how to use them to enhance security. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to learn about file ownership, permissions, and security.

In a virtual data center the deployment and the dismissal of complex appliances require that multiple configuration steps be executed. Reconfiguration requirements include establishing and removing communication between different components of the same product running in different virtual machines (VMs) as well as different products running in different VMs. Traditionally this process has been burdensomely manual or somewhat inflexible via the invoking of predefined scripts with static values. In this article, the authors propose StereoCable, automated plug-and-play support of complex virtual appliances in a virtual data center, to solve this issue. This way VMs are able to discover and automatically connect to each other based on predefined connections policies.

Up to now, you have moved your application to the cloud and can enable and disable resources automatically in response to demand. In this article, the fourth in a series on migrating a Linux application to the Amazon cloud, learn how to keep this changing environment under control so that it supports your application and business.

Learn to mount your Linux filesystems; configure and use removable USB, IEE 1394, or other devices; and properly access floppy disks, CDs, and DVDs. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to learn about accessing Linux filesystems.

In kernel development, we useprintk for logging without much thought. But have you considered the process and underlying implementation of kernel logging? Explore the entire process of kernel logging, from printk to insertion into the user space log file.

Linux systems are often installed on multiple partitions, each of which has a fixed size. As your needs change, though, it is often necessary to resize partitions to suit your changing needs. Several tools exist to do this in Linux, but there are a number of potential pitfalls and restrictions that can make the task more difficult than it might at first seem. This article covers advanced partition resizing issues, including using Logical Volume Management (LVM) features, troubleshooting, and alternatives to partition resizing. Part 1 of this series covered basic partition resizing.

POSIX thread (pthread) programming defines a standard set of C programming language types, functions, and constants--and pthreads provide a powerful tool for thread management. To use pthreads to the fullest, you'll want to avoid the common mistakes. One common mistake is forgetting to join joinable threads, which can create memory leaks and cause extra work. In this tips-oriented article, learn the basics of POSIX threads, see how to identify and detect thread memory leaks, and get solid advice for avoiding them.

Learn how to download and install Rational Application Developer for WebSphere, DB2 Express-C, and a few other third party packages to get the solution stack up and running. This 4-part demo series shows you how to implement the solution stack (Rational Application Developer, WebSphere Application Server, and DB2 Express-C) on Ubuntu Linux, and how to integrate them in a Java application.

Learn how to configure and setup Rational Application Developer, create a WebSphere profile, create a database in DB2 Express-C, and perform a test run on the solution stack. This 4-part demo series shows you how to implement the solution stack (Rational Appli-ation Developer, WebSphere Application Server, and DB2 Express-C) on Ubuntu Linux, and how to integrate them in a Java application.

Linux systems are often installed on multiple partitions, each of which has a fixed size. As your needs change, though, it is often necessary to resize partitions to suit your changing needs. Several tools exist to do this in Linux, but there are a number of potential pitfalls and restrictions that can make the task more difficult than it might seem at first. This article guides you through the task of resizing Linux partitions, beginning with basic preparations and moving on to common resizing scenarios using graphical user interface (GUI) tools.

In this article, the second in a series on migrating a Linux application to the Amazon cloud, learn how to make your application more robust by employing a load balancer and persistent disk. You'll use multiple servers and learn how to safely back up your data.

Learn how to download and install a Ubuntu image and then go through some basic shell commands to help you navigate through the UNIX environment. This is part 1 of a 4 part demo series to show you how to implement a solution stack (Rational Application Developer, WebSphere Application Server, and DB2 Express-C) on Ubuntu Linux, as well as how to integrate them in a Java application.

With configuration, installation, and the use of Hadoop in single- and multinode architectures under your belt, you can now turn to the task of developing applications within the Hadoop infrastructure. This final article in the series explores the Hadoop APIs and data flow and demonstrates their use with a simple mapper and reducer application.

Learn how to create partitions on a disk drive and how to format them for use on a Linux system as swap or data space. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to learn about partitions and Linux filesystems for your own use.

The first article in this series showed how to use Hadoop in a single-node cluster. This article continues with a more advanced setup that uses multiple nodes for parallel processing. It demonstrates the various node types required for multinode clusters and explores MapReduce functionality in a parallel environment. This article also digs into the management aspects of Hadoop -- both command line and Web based.

Learn how to create and manage hard and symbolic links to files on your Linux system. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to explore the differences between hard and soft, or symbolic, links and the best ways to link to files, as opposed to copying files.

This article -- the first in a series on Hadoop -- explores the Hadoop framework, including its fundamental elements, such as the Hadoop file system (HDFS), and node types that are commonly used. Learn how to install and configure a single-node Hadoop cluster, and delve into the MapReduce application. Finally, discover ways to monitor and manage Hadoop using its core Web interfaces.

Learn how to install, upgrade and manage packages on your Linux system. This article focuses on the Red Hat Package Manager (RPM) developed by Red Hat, as well as the Yellowdog Updater Modified (YUM) originally developed to manage Red Hat Linux systems at Duke University's Physics department. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to explore the best ways to add new software and keep your system current.

Starting in December 2009, hard disk manufacturers began introducing disks that use 4096-byte sectors rather than the more common 512-byte sectors. Although this change is masked by firmware that breaks the 4096-byte physical sectors into 512-byte logical sectors for the benefit of the operating system, the use of larger physical sectors has implications for disk layout and system performance. This article examines these implications, including benchmark tests illustrating the likely real-world effects on some common Linux file systems. As disks with 4096-byte sectors become more common throughout 2010 and beyond, strategies for coping with these new disks will become increasingly important.

The tools used to boot Linux are changing. Specifically, the Grand Unified Bootloader (GRUB) is now officially in maintenance mode only, and GRUB's developers have abandoned the original GRUB in favor of an entirely rewritten package, known as GRUB 2. Discover GRUB 2's new capabilities and how to use it.

Linux as a hypervisor includes a number of innovations, and one of the more interesting changes in the 2.6.32 kernel is Kernel Shared Memory (KSM). KSM allows the hypervisor to increase the number of concurrent virtual machines by consolidating identical memory pages. Explore the ideas behind KSM (such as storage de-duplication), its implementation, and how you manage it.

Learn how to determine which shared libraries your Linux executable programs depend on and how to load them. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to learn for fun.

For high-frequency threaded operations, the Linux kernel provides tasklets and work queues. Tasklets and work queues implement deferrable functionality and replace the older bottom-half mechanism for drivers. This article explores the use of tasklets and work queues in the kernel and shows you how to build deferrable functions with these APIs.

The Linux system call interface permits user-space applications to invoke functionality in the kernel, but what about invoking user-space applications from the kernel? Explore the usermode-helper API, and learn how to invoke user-space applications and manipulate their output.

Learn how to use the vi editor, found on almost every UNIX and Linux system. You can use the material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to learn for fun.

One of Linux's strengths is its cross-platform nature: you can run it on x86, x86-64, SPARC, PowerPC, and many other central processing units (CPUs). This wealth of hardware choices poses a challenge for software developers, though. Ensuring that software compiles, and runs correctly, on all platforms can be difficult. The use of the QEMU package can help ease this burden. QEMU is a machine emulator that supports a wide range of CPUs, so you can run PowerPC software on an x86 computer, x86-64 software on an SPARC computer, or what have you. This facility is particularly useful for programmers who need to test software's endianness compatibility or check other CPU-specific features. QEMU also enables you to run different operating systems entirely, so that you can test a program's ability to compile and run under FreeBSD, Solaris, or even Microsoft Windows without shutting down Linux.

Learn how to set and change process priorities so that applications get as much processing time as they need. You can use this material in this article to study for the LPI 101 exam for Linux system administrator certification, or just to learn for fun.

The Linux kernel supports a variety of virtualization schemes, and that's likely to grow as virtualization advances and new schemes are discovered (for example, lguest). But with all these virtualization schemes running on top of Linux, how do they exploit the underlying kernel for I/O virtualization? The answer is virtio, which provides an efficient abstraction for hypervisors and a common set of I/O virtualization drivers. Discover virtio, and learn why Linux will soon be the hypervisor of choice.

Hardware management using the Common Information Model standard often means that the management application must be capable of listening to and handling the indications that occur at the hardware level. To test the indication listener component of the management application when the planned system hardware is not available during development, you will need dummy indications. This article explains how to generate dummy indications on OpenPegasus CIMOM (Common Information Model Object Manager) using a provider shipped with the OpenPegasus source code.

Learn how Perl programmers can use three of the CPAN S3 modules -- Net::Amazon::S3, Amazon::S3, and SOAP::Amazon::S3 -- to list, create, and delete "buckets" (S3 data storage); to list, create, retrieve, and delete items in a bucket; and to get an item's metadata.

This series of articles explores how to use Python to create scripts for the GNOME desktop, the screenlets framework, and Nautilus to deliver a highly productive environment. Scripts on the desktop enable drag-and-drop functionality and quick access to the information and services you commonly use. In this installment, learn how to build a desktop application using the screenlets widget toolkit.

In this second article in a three-part series on the RPM Package Manager, learn how how to use RPM to upgrade and uninstall software on your Linux system. (This series replaces an earlier series on RPM written by Dan Poirier.)

The libvirt library is a Linux API over the virtualization capabilities of Linux that supports a variety of hypervisors, including Xen and KVM, as well as QEMU and some virtualization products for other operating systems. This article explores libvirt, its use, and its architecture.

Learn how to access the features of the Twitter API using the CPAN Net::Twitter module. You'll also see some solid business uses for Twitter, including automated posting and analyzing Twitter search results.

For collecting data from Web pages, the mechanize library automates scraping and interaction with Web sites. Mechanize lets you fill in forms and set and save cookies, and it offers miscellaneous other tools to make a Python script look like a genuine Web browser to an interactive Web site. A frequently used companion tool called Beautiful Soup helps a Python program makes sense of the messy "almost-HTML" that Web sites tend to contain.

Modern operating system kernels provide the means for introspection, the ability to peer dynamically within the kernel to understand its behaviors. These behaviors can indicate problems in the kernel as well as performance bottlenecks. With this knowledge, you can tune or modify the kernel to avoid failure conditions. Discover an open source infrastructure called SystemTap that provides this dynamic introspection for the Linux kernel.

Not only has virtualization advanced the state of the art in maximizing server efficiency, it has also opened the door to new technologies that were not possible before. One of these technologies is the virtual appliance, which fundamentally changes the way software is delivered, configured, and managed. But the power behind virtual appliances lies in the ability to freely share them among different hypervisors. Learn the ideas and benefits behind virtual appliances, and discover a standard solution for virtual appliance interoperability called the Open Virtualization Format.

Processors have evolved to improve performance for virtualized environments, but what about I/O aspects? Discover one such I/O performance enhancement called device (or PCI) passthrough. This innovation improves performance of PCI devices using hardware support from Intel (VT-d) or AMD (IOMMU).

Many companies like IBM, Google, VMWare, and Amazon have provided products and strategies for Cloud computing. This article shows you how to use Apache Hadoop to build a MapReduce framework to make a Hadoop Cluster and how to create a sample MapReduce application which runs on Hadoop. You will also learn how to set up a time/disk-consuming task on the cloud.

Electricity is invisible. To understand how people use it, you need to make it visible. This tutorial will show you how easy it is to build a Web-based energy monitoring system yourself, using a Current Cost real-time energy monitor and AMEE, a neutral Web-based API for energy data, combined with some XML, Ruby, Rails, and Ajax.

This three-part series is your starting point for tuning your system for power efficiency. In Part 1, get up to speed on the components and concepts you need to fine-tune a Linux-based System x server for power efficiency. Learn how to enable the Linux CPUfreq subsystem, get instruction on C and P states, and determine which of the five in-kernel governors you need to boost power efficiency on your system.

Accelerate your porting efforts by following this six-step guide. Learn the differences between Solaris and Linux on POWER that you commonly encounter during a port. Get an introduction to the development environment for Linux running on IBM POWER processor-based systems, and see how Sun's compiler/linker switches compare with those of GNU GCC and the IBM native compiler. Finally, learn about tools for performance analysis and software packaging for Linux on POWER. [This article has been updated to reflect the latest product versions. -Ed.]

Linux is the very definition of flexibility and extensibility. Take the virtual file system switch (VFS). You can create file systems on a variety of devices, from traditional disk, USB flash drives, memory, and other storage devices. You can even embed a file system within the context of another file system. Discover what makes the VFS so powerful, and learn its major interfaces and processes.

Outdated computer hardware may be too old to rely on, but it represents a value to your organization -- whether in an office or at home. Discover how you can realize that value by repurposing older machines with Linux.

The O'Reilly Open Source Convention (OSCON) is nothing if not a place to collect one's deeper thoughts around software development. The 2009 convention offered more than its share of inspiration, but David Mertz whittled the schedule down and focused on two very different but important areas: open government and concurrency.

Once a faraway problem, an important barrier in disk storage is fast becoming a reality: the venerable master boot record (MBR) partitioning scheme can't fully handle disks larger than 2TB. With 1TB-hard disks now common and 2TB-disks becoming available, forward-looking individuals are thinking about alternatives to the MBR partitioning scheme. The heir apparent is the GUID Partition Table (GPT). Learn how to make sure your Linux system is fully prepared for the future of disk storage.