Hardware Requirements

In the first section of this chapter, you learned to consider how Linux can be used in your environment and how you can prepare for its installation and deployment. These considerations also play a role in determining the types of hardware you need in your installation. But the type of deployment you choose also determines the hardware required for a successful deployment of Linuxand post-deployment satisfaction. The range of Linux hardware requirements and compatible hardware types is quite wide, especially when you consider that Linux can be used with mainframe computers as well as embedded devices.

Meeting the Minimum Fedora Core Hardware Requirements

The Fedora Project publishes general minimum hardware requirements for installing and using its base distribution in a file named RELEASE NOTES on the first CD-ROM or DVD, or available at http://fedora.redhat.com/docs/release-notes/. For the current release, your PC should at least have a 200MHz Pentium CPU, 620MB hard drive space, and 64MB RAM for using (and installing) Fedora without a graphical interface. For obvious reasons, a faster CPU, larger capacity hard drive, and more RAM are desired. Servers and development workstations require more storage and RAM.

Using Legacy Hardware

If you have an older PC based on an Intel 486 CPU with only 32MB RAM and a 500MB hard drive (which can be hard to find nowadays), you can install other Linux distributions such as Debian from The Debian Project at http://www.debian.org/.

Caution

One caveat is that if you prepare a hard drive with Linux in a PC with one CPU, such as a Pentium, and then install the drive in a PC with a 486 CPU, you should either make sure that a 486-based Linux kernel is installed, or perform a post-install of an appropriate kernel after moving the hard drive.

Installing Fedora on legacy hardware will be easier if you choose to use more recent Pentium-class PCs, but even older Pentium PCs can be used and purchased at a fraction of their original cost. Such PCs can easily handle many mundane but useful tasks. Some of the tasks suitable for older hardware include

• Acting as a firewall, router, or gateway

• Audio jukebox and music file storage server

• Handling electronic mail

• Hosting a remote printer and providing remote printing services

• Network font server

• Providing FTP server access

• Remote logging capture

• Secondary network-attached backup server

• Serving as an Intranet (internal LAN) web server

• Unattended dial-up gateway, voice mailbox, or fax machine

• Use as a thin-client workstation for basic desktop tasks

Older PCs can handle any task that does not require a CPU with a lot of horsepower. To get the most out of your hardware, do not install any more software than required (a good idea in any case, especially if you are building a server). To get a little performance boost, add as much RAM as economically and practically feasible . If you cannot do this, cut down on memory usage by turning off unwanted or unneeded services. You can also recompile a custom Linux kernel to save a bit more memory and increase performance (see Chapter 39, "Kernel and Module Management").

Note

Fedora does not include XFree86 3.3.6. This version might be important because older, legacy video cards are no longer supported in the newer X11R6.8.2 distribution. You can download version 3.3.6 from The XFree86 Project, Inc. through http://ftp.xfree86.org/pub/XFree86/3.3.6/binaries/. Make sure to choose the appropriate version for your operating system!

Planning for Hard Drive Storage for Your Fedora Installation Class

Making room for Fedora requires you to decide on how to use existing hard drive space. You might decide to replace existing hard drives entirely, for example, or you might decide to use only one operating system on your computer, making partitioning unnecessary. A full install from this book's DVD will require at least 7GB hard drive space just for the software, so if you plan to install everything, a 10GB hard drive could be ideal for a workstation. Note that depending on how you plan to use Linux, a smaller capacity disk can be used, or a disk capacity many times the size of your system will be required.

Note

The following recommended installations and minimal storage requirements are based on a full install of the freely available version of Fedora Core distributed on the Internet. The copy of Fedora included with this book is the same, but you might find many additional software packages available from third-party Fedora contributors. Installing additional software will affect your storage requirements.

The Fedora installer offers a choice of installation types or classes, and each has its own hard drive storage requirements:

• Workstation You will need a minimum of 3GB hard drive storage, but much more if you choose to install everything. This installation is intended for developers and other users who want to use the entire spectrum of Linux software offered by the distribution.

• Personal Desktop This installation class is for SOHO ( small office / home office ) users and installs a basic graphical desktop, along with requisite office and Internet productivity software; you will need around 2.3GB of storage if you do not customize the default software selections.

• Server You need at least 1.1GB of storage for the operating system and server software, but you also must take into consideration other storage requirements. For example, if you plan to run a website with a lot of graphics or serve other files, you might need to add storage to your system or accommodate remotely mounted storage locally.

• Custom This installation supports a minimal install requiring a little more than 600MB; however, you can also choose to install all the software in the distribution; in which case, you'll need 7GB or more of storage, along with several hundred megabytes of free space for temporary files.

The storage requirements for each of these classes can be revised somewhat, depending on the X desktop environment you choose (such as KDE or GNOME). Choosing the Custom install lets you choose specific software packages from the group package categories. Here are some software packages you might want to consider passing up in the installation process for a minimalist system:

• X Window System

• GNOME desktop environment

• KDE desktop environment

• Graphical Internet

• Office/productivity

• Documentation

• Sound and video

• Graphics

• All development software or libraries

Checking Hardware Compatibility

Fedora software for Intel-based PCs is compiled for the minimum x86 platform supported by the Linux kernel.

Note

The compatibility information in this chapter relates to Fedora. Other distributions might have different storage and CPU requirements. Also bear in mind that Fedora is available for x86-64 and PPC architectures as well. Consult the release notes to get a detailed specification for these versions.

Specific issues regarding Linux hardware compatibility can be researched online at a number of sites. Red Hat offers a hardware compatibility database at http://hardware.redhat.com/hcl/. You can select hardware class, manufacturer, version of Red Hat Enterprise Linux, platform, and status of support.

Other sites, such as the Linux-USB device overview at http://www.qbik.ch/usb/devices/, offer an interactive browsing of supported devices, and printer compatibility can be researched at LinuxPrinting.org at http://linuxprinting.org/. Some hardware categories to consider in your research include

• Controller cards Such as SCSI, IDE, SATA, FireWire

• CPUs Intel, AMD, Power, 64-bit, and Dual Core

• Input devices Keyboards

• Modems External, PCMCIA, PCI, and controllerless workarounds

• Network cards ISA, PCI, USB, and others

• Pointing devices Mice, tablets, and possibly touchscreens

• Printers Various printer models

• RAM Issues regarding types of system memory

• Sound cards Issues regarding support

• Specific motherboard models Compatibility or other issues

• Specific PCs, servers, and laptop models Compatibility reports , vendor certification

• Storage devices Removables, fixed, and others

• Video cards Console issues (X compatibility depends on version of X11R6 or vendor-based X distribution used)

If you have a particular laptop or PC model, you should also check with its manufacturer for Linux support issues. Some manufacturers such as HP now offer a Linux operating system preinstalled, or have an in-house Linux hardware certification program. Laptop users will definitely want to browse to Linux on Laptops at http://linux-laptop.net/.

If you cannot find compatibility answers in various online databases, continue your research by reading the Linux Hardware HOWTO at http://www.tldp.org/HOWTO/Hardware-HOWTO/. At that address, you will find loads of general information and links to additional sources of information.

Keep in mind that when PC hardware is unsupported under Linux, it is generally because the manufacturer cannot or will not release technical specifications or because no one has taken the time and effort to develop a driver. If you hit a roadblock with a particular piece of hardware, check the hardware manufacturer's support web pages, or Google's Linux pages at http://www.google.com/linux. You can then type in a specific search request and hopefully find answers to how to make the hardware work with Linux. This is also a good way to research answers to questions about software issues.

Preparing for Potential Hardware Problems

Fedora will work out-of-the-box with nearly every Intel- or PowerPC-based motherboard and laptop; drivers for thousands of different types of hardware peripherals are included. But you can sometimes run into problems if Linux does not recognize a hardware item, if Fedora does not correctly initialize the hardware, or if an initialized item is incorrectly configured. For these reasons, some hardware items are prone to creating problems during an install. In the sections that follow, you learn some important pointers for avoiding these problems or resolving those that do occur.

Controllerless Modems

As you read earlier, most Linux hardware- related installation problems stem from a lack of technical specifications from the manufacturer, thwarting efforts of open source developers to create a driver. In the recent past, one hardware item that triggered both types of difficulties was the controllerless modem, also colloquially known as a WinModem . The good news is that modem chipset manufacturers have been more forthcoming with driver details. Some original equipment manufacturers, such as IBM, have made a concerted effort to provide Linux support. Support for the ACP Mwave modem, used in ThinkPad 600/Es and 770s, is included in the Linux kernel. Drivers have been developed for many of the controllerless modem chipsets that formally did not work with Linux.

If a driver is not available for your controllerless modem, you have a few options. You can download the driver's source code and build the driver yourself. Alternatively, you can download a binary-only software package and install the driver.

Some controllerless modems might also need to be initialized and configured using a separate utility program. The modem, if supported, should work normally after installing and configuring the driver.

You can research Linux support for controllerless modems by browsing to http://www.linmodems.org/.

Universal Serial Bus Devices

Fedora supports hundreds of different Universal Serial Bus ( USB ) devices. USB is a design specification and a protocol used to enable a host computer to talk to attached peripherals. Because of lack of manufacturer and device ID information or lack of technical specifications regarding certain chipsets, some devices might not work with Fedora. USB 1.1 devices are designed to support data transfer speeds between 1.5 and 12Mbps.

Common USB devices include cameras , keyboards, mice, modems, network interfaces, printers, scanners , storage devices, video (such as webcams), and hubs (to chain additional devices). Some problematic USB devices (at the time of this writing) include

• Wireless Many 802.11b/g wireless USB network adapters, with the exception of those using Atmel chipsets

• Scanners Many Canon, Visioneer, and Hewlett-Packard USB scanners

• Webcams Selected Logitech and Creative Labs webcams

Although some enlightened manufacturers are aware of opportunities in the Linux marketplace , most still do not support Linux. It pays to determine Linux support before you buy any USB device; again, research Linux USB support and its current state of development by browsing to http://www.qbik.ch/usb/devices/.

The newer USB 2.0 specification enables devices (such as hard and CD drives) to use speeds up to 480Mbps. Fedora supports USB 2.0 with the ehci-hcd kernel module. This driver, in development since early 2001, enables the use of many forms of newer USB 2.0 devices as long as you have a supported USB controller. Check out the current state of Linux USB 2.0 support by browsing to http://www.linux-usb.org/usb2.html.

Motherboard-Based Hardware

Small form factor PCs, thin clients , notebooks , and embedded devices are part of a growing trend in the PC industry. Manufacturers are cramming more functionality into fewer chips to simplify design and lower power requirements. Today, many computers come with built-in video graphics, audio chipsets, and network interfaces, along with a host of peripheral support.

Common modern (1996-onward) PC motherboard form factors are designed according to industry-assigned specifications (usually from Intel), and are ATX (129.6 inches); MicroATX (9.69.6 inches); and FlexATX (97.5 inches). One of the newest and even smaller motherboard forms is from VIA Technologies, Inc.the mini-ITX (approximately 6.56.5 inches), which has an embedded CPU. CPUs commonly used in all these motherboards will vary, and have different socketing requirements based on chipset pins: Socket 478 for K7-type CPUs (from AMD); Socket 370 for Pentium IIIs and Celerons from Intel, or C3s from VIA; and Socket 478 for Intel's Pentium 4s (early versions of which used a 423-pin socket). Older socket types are Socket A, Socket 7 (and Super 7), Slot 1, and Slot 2.

Fortunately, nearly all controllers, bridges, and other chipsets are supported by Linux. Although flaky or unsupported built-in hardware can (usually) be sidestepped by installing a comparable PCI card component, cutting-edge notebook users are at the most risk for compatibility problems because internal components are not user - replaceable . Potential pitfalls can be avoided through careful research (vote with your money for Linux-compatible hardware), or by choosing PC motherboards with a minimum of builtin features, and then using PCI ( Peripheral Component Interconnect ) or AGP ( Accelerated Graphics Port ) cards known to work.

CPU, Symmetric Multiprocessing, and Memory Problems

Fedora supports all Intel-based Pentium CPUs. Code is included in the Linux kernel to recognize the CPU type when booting, and to then implement any required fixes to overcome architecture bugs (such as the now-infamous divide-by-zero error). After you install Fedora Core, you can also rebuild the Linux kernel to specifically support and take advantage of the host PC's CPU. You might not realize extreme improvements in computational speed, but you'll be assured that Linux is crafted for your CPU's architecture, which can help stability and reliability. Details about rebuilding the Linux kernel are in Chapter 39. Some of the Intel-based CPUs with specific supporting code for Linux include those from Advanced Micro Devices, Transmeta, and VIA Technologies.

Fedora's Linux kernel also should automatically recognize and use the amount of installed RAM. The Linux kernel should also recognize and map out any memory holes in system memory (perhaps used for video graphics).

If you are installing Fedora on a working, stable PC, you should not have any problems related to the system's memory. If you are putting together a new system, you need to avoid combining or configuring the system in ways that will interfere with its capability to process data. Some issues to be aware of are

• Do not expect similar CPU performance across product lines from different manufacturers, such as AMD or VIA. Some CPU models offer better floating point or integer math operations, which are important for a number of CPU- intensive tasks (such as graphics, audio, and video rendering or conversion). If you need better performance, try to find a faster CPU compatible with your motherboard, or switch to a CPU with better Floating Point Unit ( FPU ) performance.

• Overclocking can cause problems with overheating , memory access, and other hardware performance, and it is not a good idea for any Linux system. Overclocking is a popular geek pastime and a great way to get a bit of performance boost out of slower CPUs by altering voltage settings and/or clock timings via the BIOS. You can try to push your CPU to higher speeds, but this approach is not recommended if your aim is system stability. The Linux kernel will report the recognized CPU speed on booting (which you can view using the dmesg command).

• Along the same lines, CPU and motherboard overheating will cause problems. Proper attachment of the CPU's heatsink using a quality thermal paste (never use thermal tape), along with one or more fans providing adequate airflow lessens the chance of hardware damage and system failure.

• You can run into problems if you switch the type of CPU installed in your computer, and especially if your PC's BIOS does not automatically recognize or configure for newly installed mainboard hardware and components. In some instances, a system reinstall is warranted, but BIOS issues should be resolved first.

• Not all CPUs support symmetric multiprocessing, or SMP. Fedora readily supports use of two or more CPUs and, during installation, automatically installs an appropriate Linux kernel. You can avoid problems by reading the Linux SMP HOWTO (available through http://www.tldp.org/). Note that some CPUs, such as the current crop of VIA C3s, might not be used for SMP. Also, SMP motherboards require that all CPUs be identical. This means that you need two identical CPUs to take advantage of SMP.

• Faulty or bad memory causes Linux kernel panics or Signal 11 errors (segmentation faults), causing a system crash or a program to abort execution. Linux is quite sensitive to faulty hardware, but runs with great stability in a correctly configured system with good hardware. Problems can arise from incorrect BIOS settings, especially if video memory must occupy and use a portion of system RAM. Always install quality (and appropriate) memory in your PC to avoid problems.

Preparing and Using a Hardware Inventory

Buying a turn -key Linux solution is one way to avoid hardware problems, and many vendors are standing by, ready to prescribe solutions. However, managing deployments aimed at using existing hardware requires some information collection.

If you are a small business or individual user, you are well advised to prepare detailed checklists of existing hardware before attempting a migration to Linux. Not only do you benefit from the collected information, but you might also be able to sidestep or anticipate problems before, during, or after installation. Problems are most likely to occur with newer hardware, cutting-edge hardware such as new motherboard chipsets and video cards, or extraneous hardware such as operating system-specific scanners, printers, or wireless devices.

Table 2.2 provides a comprehensive checklist you can use to take inventory of target hardware, such as the computer and any peripherals. Veteran Linux users can take the collected information to build custom systems by adding known hardware or substituting cheaper but equivalent hardware.

Table 2.2. System and Peripheral Inventory Checklist

Use the checklist in Table 2.2 as a general guideline for recording your computer's hardware and other capabilities. You can get quite a bit of information through hardware manuals or other documentation included with your PC, video, sound, or network interface card. Don't worry if you cannot fill out the entire checklist; Fedora will most likely recognize and automatically configure your PC's hardware during installation. Much of this information can be displayed by the dmesg command after booting. However, some of these details, such as your video card's graphics chipset and installed video RAM, can come in handy if you need to perform troubleshooting. You can also use the list as a postinstallation check-off sheet to see how well Fedora works with your system.