1. Introduction and General Information

1.1 What is Linux?

Linux is the kernel of operating systems that look like and perform as well or better than the famous operating system from AT&T Bell Labs. Linus Torvalds and a loosely knit team of volunteer hackers from across the Internet wrote (and still are writing) Linux from scratch. It has all of the features of a modern, fully fledged operating system: true multitasking, threads, virtual memory, shared libraries, demand loading, shared, copy-on-write executables, proper memory management, loadable device driver modules, video frame buffering, and TCP/IP networking.

Most people, however, refer to the operating system kernel, system software, and application software, collectively, as "Linux," and that convention is used in this FAQ as well.

Linux was written originally for 386/486/586-based PC's, using the hardware facilities of the 80386 processor family to implement its features. There are now many ports to other hardware platforms. ("Ports to Other Processors.")

There are also Linux distributions specifically for mobile and handheld platforms. An API specification and developers kit for the Crusoe Smart Microprocessor developed by Transmeta Corporation are at http://www.transmeta.com/. Information on the Linux distribution for the Compaq iPAQ is at http://www.handhelds.org/

Refer also to the Linux INFO-SHEET for more details as well as the answers to "Where Is the Documentation?", "What Hardware Is Supported?", and "Ports to Other Processors.", below. A list updated weekly is at: http://lwn.net/ Archive of many of the distributions are on line at: ftp://ftp.tux.org/ and http://planetmirror.com/pub/linux.

The Linux kernel is distributed under the GNU General Public License. ("What Is Linux's Open-Source License?")

There is a historical archive of all versions of the Linux kernel at http://ps.cus.umist.ac.uk/~rhw/kernel.versions.html.

Table of Contents 1

1.2 How to Get Started

There are a handful of major Linux distributions. For information about them, and how they are installed, see Matthew Welsh's Installation and Getting Started, or IGS for short. It's located at the Linux Documentation Project Home Page, http://www.linuxdoc.org/, and on the Linux FAQ home page, http://www.mainmatter.com/

The information in IGS is somewhat dated now. More up-to-date information about first-time Linux installation is located in the LDP's Installation HOWTO, also located at the LDP Home Page.

Postings on the Usenet News groups, including the FAQ, are archived on http://groups.google.com/. Search for "comp.os.linux.*," "alt.uu.comp.os.linux.*, or whatever is appropriate, to retrieve articles from the Linux News groups. ("What News Groups Are There for Linux?")

Commercial distributions are available from book and electronics stores. Some hardware vendors now ship systems with Linux pre-installed.

There is a very thorough installation guide on line at http://heather.cs.ucdavis.edu/~matloff/linux.html.

Some distributions can still be installed via anonymous FTP from various Linux archive sites, but in many cases, the size of the distribution makes this impractical. ("Where Are the Linux FTP Archives?") There are also a large number of releases which are distributed less globally that suit special local and national needs. Many of them are archived at ftp://ftp.tux.org/

Table of Contents 1

1.3 What Software does Linux Support?

All of the standard open source utilities, like GCC, (X)Emacs, the X Window System, all the standard Unix utilities, TCP/IP (including SLIP and PPP), and all of the hundreds of programs that people have compiled or ported to it.

There is a DOS emulator, called DOSEMU. The latest stable release is 0.98.3. The FTP archives are at ftp://ftp.dosemu.org/dosemu The Web site is http://www.dosemu.org.

The emulator can run DOS itself and some (but not all) DOS applications. Be sure to look at the README file to determine which version you should get. Also, see the DOSEMU-HOWTO (slightly dated at this point--it doesn't cover the most recent version of the program), at ftp://metalab.unc.edu/pub/Linux/docs/HOWTO.

Work has been progressing on an emulator for Microsoft Windows binaries. ("Can Linux Run Microsoft Windows Programs?")

iBCS2 (Intel Binary Compatibility Standard) emulator code for SVR4 ELF and SVR3.2 COFF binaries can be included in the kernel as a compile-time option. There is information at ftp://tsx-11.mit.edu/pub/linux/BETA/ibcs2/README.

For more information see the INFO-SHEET, which is one of the HOWTO's ("Where Is the Documentation?" and "How To Port XXX to Linux.")

Some companies have commercial software available. They often announce their availability on comp.os.linux.announce-- try searching the archives. ("Are the News Groups Archived Anywhere?")

Table of Contents 1

1.4 How to Find a Particular Application

Look first in the Linux Software Map. It's at: ftp://ibiblio.org/pub/Linux/docs/linux-software-map/, and on the other FTP sites. A search engine is available on the World Wide Web at http://www.boutell.com/lsm/.

Also check out the Freshmeat Web site: http://www.freshmeat.net, which is where many new announcements of free software first appear. Freshmeat is basically a site index that continuously updates the notices of new or upgraded software for Linux, and maintains indexes of the announcements and links to their URL's.

The FTP sites ("Where Are the Linux FTP Archives?") often have ls-lR or INDEX directory listings which you can search using grep or a text editor. The directory listings files can be very large, however, making them unwieldy for quick searches.

Also look at the Linux Projects Map: ftp://ftp.ix.de/pub/ix/Linux/docs/Projects-Map.gz.

There's a search engine for Linux FTP archives at: http://lfw.linuxhq.com/.

Searching for "Linux" on the World Wide Web provides copious references. ("Where Is the Linux Stuff on the World Wide Web?")

If you don't find anything, you could download the sources to the program yourself and compile them. See (See: "How To Port XXX to Linux.") If it's a large package that may require some porting, post a message to comp.os.linux.development.apps.

If you compile a large-ish program, please upload it to one or more of the FTP sites, and post a message to comp.os.linux.announce (submit your posting to linux-announce@news.ornl.gov).

If you're looking for an application program, the chances are that someone has already written a free version. The comp.sources.wanted FAQ has instructions for finding the source code.

Table of Contents 1

1.5 What Hardware Is Supported?

A minimal Linux installation requires a machine for which a port exists, at least 2Mb of RAM, and a single floppy drive. But to do anything even remotely useful, more RAM and disk space are needed. Refer to: "Ports to Other Processors.", "Disk Space Requirements: Minimal, Server, and Workstation.", and "Minimum and Maximum Memory Requirements."

Intel CPU, PC-compatible machines require at least an 80386 processor to run the standard Linux kernel.

Linux, including the X Window System GUI, runs on most current laptops. Refer to the answer for: "How To Find Out If a Notebook Runs Linux." There are numerous sources of information about specific PC's, video cards, disk controllers, and other hardware. Refer to the INFO-SHEET, Laptop HOWTO, and the Hardware HOWTO. ("Where Is the Documentation?")

Table of Contents 1

1.6 Ports to Other Processors

The Web site, Overview of Linux Ports: http://www.itp.uni-hannover.de/~kreutzm/de/lin_plattforms.html provides a listing of known ports.

Another site with a list of ports is: http://lodda.igo.uni-hannover.de/ports/linux_ports.html

In addition, the following information is available about specific ports:

On Intel platforms, VESA Local Bus and PCI bus are supported.

MCA (IBM's proprietary bus) and ESDI hard drives are mostly supported. There is further information on the MCA bus and what cards Linux supports on the Micro Channel Linux Web page, http://www.dgmicro.com/mca. Refer also to the answer for: "Where Is the Linux Stuff on the World Wide Web?"

There is a port of Linux to the 8086, known as the Embeddable Linux Kernel Subset (ELKS). This is a 16-bit subset of the Linux kernel which will mainly be used for embedded systems, at: http://www.linux.org.uk/Linux8086.html. Standard Linux does not run 8086 or 80286 processors, because it requires task-switching and memory management facilities found on 80386 and later processors.

Linux supports multiprocessing with Intel MP architecture. See the file Documentation/smp.tex in the Linux kernel source code distribution.

A project has been underway for a while to port Linux to suitable 68000-series based systems like Amigas and Ataris. The Linux/m68K FAQ is located at http://www.clark.net/pub/lawrencc/linux/faq/faq.html. The URL of the Linux/m68k home page is http://www.linux-m68k.org/faq/faq.html.

There is a m68k port for the Amiga by Jes Sorensen, which is located at ftp://sunsite.auc.dk/pub/os/linux/680x0/redhat/. The installation FAQ for the package, by Ron Flory, is at http://www.feist.com/~rjflory/linux/rh/.

There is also a linux-680x0 mailing list. ("What Mailing Lists Are There?")

There is (or was) a FTP site for the Linux-m68k project on ftp.phil.uni-sb.de/pub/atari/linux-68k, but this address may no longer be current.

Debian GNU/Linux is being ported to Alpha, Sparc, PowerPC, and ARM platforms. There are mailing lists for all of them. See http://www.debian.org/MailingLists/subscribe

One of the Linux-PPC project pages has moved recently. Its location is http://www.debian.org/MailingLists/subscribe. http://www.linuxppc.org, and the archive site is ftp://ftp.linuxppc.org/linuxppc.

There is a Linux-PPC support page at http://www.cs.nmt.edu/~linuxppc/. There you will find the kernel that is distributed with Linux.

There are two sites for the Linux iMac port: http://w3.one.net/~johnb/imaclinux, and http://www.imaclinux.net:8080/content/index.html.

A port to the 64-bit DEC Alpha/AXP is at http://www.azstarnet.com/~axplinux/. There is a mailing list at vger.redhat.com: ("What Mailing Lists Are There?")

Ralf Baechle is working on a port to the MIPS, initially for the R4600 on Deskstation Tyne machines. The Linux-MIPS FTP sites are ftp://ftp.fnet.fr/linux-mips and ftp://ftp.linux.sgi.com/pub/mips-linux. Interested people may mail their questions and offers of assistance to linux@waldorf-gmbh.de.

There is (or was) also a MIPS channel on the Linux Activists mail server and a linux-mips mailing list. ("What Mailing Lists Are There?")

There are currently two ports of Linux to the ARM family of processors. One of these is for the ARM3, fitted to the Acorn A5000, and it includes I/O drivers for the 82710/11 as appropriate. The other is to the ARM610 of the Acorn RISC PC. The RISC PC port is currently in its early to middle stages, owing to the need to rewrite much of the memory handling. The A5000 port is in restricted beta testing. A release is likely soon.

For more, up-to-date information, read the newsgroup comp.sys.acorn.misc. There is a FAQ at http://www.arm.uk.linux.org.

The Linux SPARC project is a hotbed of activity. There is a FAQ and plenty of other information available from the UltraLinux page, http://www.ultralinux.org/.

The Home Page of the UltraSPARC port ("UltraPenguin") is located at http://sunsite.mff.cuni.cz/linux/ultrapenguin-1.0/, although the URL may not be current.

There is also a port to SGI/Indy machines ("Hardhat"). The URL is http://www.linux.sgi.com/.

Table of Contents 1

1.7 Disk Space Requirements: Minimal, Server, and Workstation

About 10Mb for a very minimal installation, suitable for trying Linux, and not much else.

You can fit a typical server installation, including the X Window Systemt GUI, into 80Mb. Installing Debian GNU/Linux takes 500Mb-1GB, including kernel source code, some space for user files, and spool areas.

Installing a commercial distribution that has a desktop GUI environment, commercial word processor, and front-office productivity suite, will claim 1-1.5 GB of disk space, approximately.

Table of Contents 1

1.8 Minimum and Maximum Memory Requirements

At least 4MB, and then you will need to use special installation procedures until the disk swap space is installed. Linux will run comfortably in 4MB of RAM, although running GUI apps is impractically slow because they need to swap out to disk.

Some applications, like StarOffice, require 32 MB of physical memory, and compiling C++ code can easily consume over 100 MB of combined physical and virtual memory.

There is a distribution, "Small Linux," that will run on machines with 2MB of RAM. Refer to the answer to: "Where Are the Linux FTP Archives?"

A number of people have asked how to address more than 64 MB of memory, which is the default upper limit in most standard kernels. Either type, at the BOOT lilo: prompt:

mem=XXM

Or place the following in your /etc/lilo.conf file:

append="mem=XXM"

The parameter "XXM" is the amount of memory, specified as megabytes; for example, "128M."

If an "append=" directive with other configuration options already exists in /etc/lilo.conf, then add the mem= directive to the end of the existing argument, and separated from the previous arguments by a space; e.g.:

# Example only; do not use.
append="parport=0x3bc,none serial=0x3f8,4 mem=XXM"

Be sure to run the "lilo" command to install the new configuration.

If Linux still doesn't recognize the extra memory, the kernel may need additional configuration. Refer to the /usr/src/linux/Documentation/memory.txt file in the kernel source as a start.

For further information about LILO, refer to the manual pages for lilo and lilo.conf, the documentation in /usr/doc/lilo, and the answer for: "Boot-Time Configuration.", below.

Table of Contents 1

1.9 Does Linux Support Universal System Bus Devices?

Linux supports a few dozen USB devices at present, and work is underway to develop additional device drivers. There is a Web page devoted to the subject, at http://www.linux-usb.org/. There is also LDP documentation, at: ("Where Is the Linux Stuff on the World Wide Web?")

Table of Contents 1

1.10 What Is Linux's Open-Source License?

The Linux trademark belongs to Linus Torvalds. He has placed the Linux kernel under the GNU General Public License, which basically means that you may freely copy, change, and distribute it, but you may not impose any restrictions on further distribution, and you must make the source code available.

There is a FAQ for the GPL at: http://www.gnu.org/copyleft/gnu-faq.html.

This is not the same as Public Domain. See the Copyright FAQ, ftp://rtfm.mit.edu/pub/usenet/news.answers/law/copyright, for details.

Full details are in the file COPYING in the Linux kernel sources (probably in /usr/src/linux on your system).

The licenses of the utilities and programs which come with the installations vary. Much of the code is from the GNU Project at the Free Software Foundation, and is also under the GPL.

Note that discussion about the merits or otherwise of the GPL should be posted to the news group gnu.misc.discuss, and not to the comp.os.linux hierarchy.

For legal questions, refer to the answer: ("Where Are Linux Legal Issues Discussed?")

Table of Contents 1

1.11 Is Linux *nix?

Not officially, until it passes the Open Group's certification tests, and supports the necessary API's. Even very few of the commercial operating systems have passed the Open Group tests. For more information, see http://www.unix-systems.org/what_is_unix.html.
[Bob Friesenhahn]

Table of Contents 1
2. Network Sources and Resources

2.1. Where Is the Latest Kernel Version on the Internet?

Make that versions. The 2.0 series kernels are still available for older machines. The latest production kernel series is 2.2.x. The updates to this kernel are bug fixes. The new 2.4 kernel sources are also on-line.

The Web page at http://www.kernel.org/ lists the current versions of the development and production kernels.

If you want to download the source code, FTP to ftp.xx.kernel.org, where "xx" is the two-letter Internet domain abbreviation of your country; e.g., "us" for United States, "ca" for Canada, or "de" for Germany. Kernel versions 2.2.x are archived in the directory pub/linux/kernel/v2.2, as are patches for the prerelease versions. The kernel source code is archived as a .tar.gz file, and as a .tar.bz2 file.

Follow the instructions in any of the standard references to compile the kernel, as you would with any other custom kernel. The Documentation subdirectory contains information by the authors of various subsystems and drivers, and much of that information is not documented elsewhere.

If you want to participate in kernel development, make sure that you sign on to the linux-kernel mailing list to find out what people are working on. Refer to the answer: "What Mailing Lists Are There?"

There is a story about the features of the 2.4 series kernels at http://features.linuxtoday.com/stories/8191.html.

Table of Contents 2

2.2. Where Is the Documentation?

Look in the following places, and the sites that mirror them.

  * http://www.linuxdoc.org/
  * ftp://ftp.funet.fi/pub/OS/Linux/doc/HOWTO/
  * ftp://tsx-11.mit.edu/pub/linux/docs/HOWTO/
  * ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/

For a list of Linux FTP sites, refer to the answer for: "Where Are the Linux FTP Archives?"

If you don't have access to FTP, try the FTP-by-mail servers: ftpmail@decwrl.dec.com, ftpmail@doc.ic.ac.uk, or: ftp-mailer@informatik.tu-muenchen.de.

A complete list of HOWTO's is available in the file HOWTO-INDEX at http://www.linuxdoc.org/HOWTO/HOWTO-INDEX/howtos.html. The mini-HOWTO's are indexed at http://www.linuxdoc.org/HOWTO/HOWTO-INDEX/mini.html.

A search engine at the Linux FAQ Home Page, http://www.mainmatter.com/, allows you to search LDP HOWTO's, the Linux FAQ, man pages, and Network Administrator's Guide.

In addition, translations are available from ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/translations/ and mirrors worldwide. The HOWTO's and other documentation have been translated into the following languages:

Chinese (Big5) (zh)   Croatian (hr)    French (fr)
German (de            Hellenic (el)    Indonesian (id)
Italian (it)          Japanese (ja)    Korean (ko)
Polish (pl)           Slovenian (sl)   Spanish (es)
Swedish (sv)          Turkish (tr)

Additional documents are always in preparation. Please get in touch with the coordinators if you are interested in writing one. Contact and submission information is at http://www.linuxdoc.org/mailinfo.html.

There is also a LDP HOWTO page at http://howto.tucows.org/.

The Guide Series produced by the Linux Documentation Project is available from http://www.linuxdoc.org/. Please read them if you are new to Unix and Linux.

The Linux Mobile Guide is an expanded version of the Linux-Laptop-HOWTO. The URL is: http://home.snafu.de/wehe/howtos.html.

And, of course, a number of people have written documentation independently of the LDP:

  * Linux Administrators Security Guide, by Kurt Seifried.
    http://www.freek.com/lasg/.
  * Newbie's Linux Manual. http://www.linuxdoc.org/nlm/.
  * One-Page Linux Manual. http://www.powerup.com.au/~squadron/.
  * Rute Users Tutorial and Exposition. http://rute.sourceforge.net/.
  * Short beginners' manual for Linux. Also available in Dutch.
    http://www.stuwww.kub.nl/people/b.vannunen/linux-man.php3.
  * Virtual Frame buffer HOWTO, by Alex Buell.
    http://www.tahallah.demon.co.uk/programming/prog.html.
  * X11 & TrueType Fonts, by Peter Kleiweg.
    http://www.let.rug.nl/~kleiweg/.

Documentation for kernel developers is on-line: http://kernelbook.sourceforge.net/.

To find out about Linux memory management, including performance tuning, see Rik van Riel's Web page at http://humbolt.geo.uu.nl/Linux-MM/.

The Linux Consultants HOWTO has a directory of Linux consultants at http://www.linuxports.com/.

Gary's Encyclopedia lists over 4,000 Linux related links. Its URL is http://members.aa.net/~swear/pedia/index.html.

There is also a FAQ specifically for the Red Hat Linux distribution, at http://www.best.com/~aturner/RedHat-FAQ/faq_index.html.

And the Home Page of this FAQ is http://www.mainmatter.com/.

Table of Contents 2

2.3. Where Is the Linux Stuff on the World Wide Web?

In addition to the Linux Documentation Project Home Page: http://www.linuxdoc.org/, there are many pages that provide beginning and advanced information about Linux.

These two pages provide a good starting point for general Linux information: Linux International's Home Page, at http://www.li.org/, and the Linux Online's Linux Home Page at http://www.linux.org/.

Both of these pages provide links to other sites, information about general information, distributions, new software, documentation, and news.

Documentation for kernel developers is on-line: http://kernelbook.sourceforge.net/.

The tutorial, Unix is a Four Letter Word..., is located at http://www.linuxbox.com/~taylor/4ltrwrd/. It is a general introduction to Unix operating systems and is not Linux specific.

Additionally, here is a certainly incomplete list of Web pages devoted to Linux:

  * AboutLinux.com: http://www.aboutlinux.com/.
  * Adventures in Linux Programming:
    http://members.tripod.com/rpragana/.
  * Dave Central Linux Software Archive:
    http://linux.davecentral.com/.
  * debianHELP http://www.debianhelp.org/.
  * Erlug Webzine (Italian): http://www.erlug.linux.it/.
  * Free Unix Giveaway List: http://visar.csustan.edu/giveaway.html.
    Lists offers of free Linux CDs. Also available via E-mail:
    axel@visar.csustan.edu, with the Subject: send giveaway_list.
  * Information on Linux in corporate environments:
    http://www.smartstocks.com/linux.html.
  * Jeanette Russo's Linux Newbie Information:
    http://www.stormloader.com/jrusso2/index.html.
  * JustLinux.com: http://www.justlinux.com/.
  * Linux Cartoons:
    http://www.cse.unsw.edu.au/~conradp/linux/cartoons/.
  * LinuxArtist.org: http://www.linuxartist.org/.
  * Linuxinfor.com - Online Linux Resources:
    http://www.linuxinfor.com/.
  * linuXChiX.org: http://www.linuxchix.org/.
  * LinuxDevices.com: The Embedded Linux Portal:
    http://www.linuxdevices.com.
  * Linux Educational Needs Posting Page:
    http://www.slip.net/~brk/linuxedpp.htm.
  * Linux in Business: Case Studies:
    http://www.bynari.com/collateral/case_studies.html.
  * Linux Hardware Database Laptop Superguide:
    http://lhd.zdnet.com/db/superguide.php3?catid=18.
  * Linux Inside: http://linuxinside.org/.
  * Linux Links: http://www.linuxlinks.com/.
  * Linux Memory Management Home Page:
    http://humbolt.geo.uu.nl/Linux-MM/.
  * Linux Newbie Project: http://kusma.hypermart.net/.
  * Linux on the Thinkpad 760ED: http://www.e-oasis.com/linux-tp.html.
  * LinuxOrbit: http://www.linuxorbit.com/
  * Linux Parallel Port Home Page:
    http://www.torque.net/linux-pp.html.
  * Linux MIDI & Sound Applications: http://sound.condorow.net/.
  * Linux Start: http://www.linuxstart.com/.
  * Linux Tips and Tricks Page: http://www.patoche.org/LTT/.
  * Linux Today PR: http://www.linuxpr.com/.
  * Mandrakeuser.Org: http://mandrakeuser.org/
  * My Linux Contributions by Richard Gooch:
    http://www.atnf.csiro.au/~rgooch/linux/.
  * Micro Channel Linux Web Page: http://www.dgmicro.com/mca/.
  * Parallel port scanners and SANE:
    http://www2.prestel.co.uk/hex/scanners.html.
  * Pascal Central: http://www.pascal-central.com/
  * PegaSoft Portal: http://www.vaxxine.com/pegasoft/portal/
  * PocketLinux. http://www.pocketlinux.com/.
  * Red Hat and ISDN4Linux: http://www.webideal.de/.
  * SearchLinux: http://www.searchlinux.com/.
  * The Free Linux CD Project: http://www.freelinuxcd.org/.
  * The Site for People Learning Perl: http://learn.perl.org/.
  * USB Linux Home Page: http://peloncho.fis.ucm.es/~inaky/uusbd-www/.
  * VLUG: The Virtual Linux Users Group: http://www.vlug.com/.

Searching for "Linux" on Web Search Engines, like Yahoo! (http://www.yahoo.com/), Altavista (http://www.altavista.com/), or Google (http://www.google.com/) will provide copious references to Linux Web sites. Further information about about Web search engines is in the Web and Internet Search Engine Faq: http://www.infobasic.com/pagefaq.html.

Refer also to the answer for: "What Other FAQ's and Documentation Are There for Linux?"

Table of Contents 2

2.4 What News Groups Are There for Linux?

Comp.os.linux.announce is the moderated announcements group. You should read this if you intend to use Linux. It contains information about software updates, new ports, user group meetings, and commercial products. It is the only newsgroup that may carry commercial postings. Submissions for that group should be e-mailed to linux-announce@news.ornl.gov.

Comp.os.linux.announce is archived at: http://www.iki.fi/mjr/linux/cola.html, and ftp://src.doc.ic.ac.uk/usenet/comp.os.linux.announce/.

Also worth reading are the following other groups in the comp.os.linux.* and alt.uu.comp.os.linux.* hierarchies--you may find many common problems too recent for the documentation but are answered in the newsgroups.

  * alt.uu.comp.os.linux
  * alt.uu.comp.os.linux.questions
  * alt.os.linux
  * alt.os.linux.mandrake
  * comp.os.linux.admin
  * comp.os.linux.advocacy
  * comp.os.linux.alpha
  * comp.os.linux.answers
  * comp.os.linux.development
  * comp.os.linux.development.apps
  * comp.os.linux.development.system
  * comp.os.linux.embedded
  * comp.os.linux.hardware
  * comp.os.linux.help
  * comp.os.linux.m68k
  * comp.os.linux.misc
  * comp.os.linux.network
  * comp.os.linux.networking
  * comp.os.linux.portable
  * comp.os.linux.powerpc
  * comp.os.linux.questions
  * comp.os.linux.redhat
  * comp.os.linux.security
  * comp.os.linux.setup
  * comp.os.linux.test
  * comp.os.linux.x
  * comp.os.linux.x.video

Remember that Linux is POSIX compatible, and most all of the material in the comp.unix.* and comp.windows.x.* groups will be relevant. Apart from hardware considerations, and some obscure or very technical low-level issues, you'll find that these groups are good places to start.

Information about e-mail clients (MUA's), mail transfer agents (MTA's), and other related software are in the comp.mail.* groups, especially:

  * comp.mail.misc
  * comp.mail.pine
  * comp.mail.sendmail

Questions and information about News reading software are in: news.software.readers.

Please read "If this Document Still Hasn't Answered Your Question...." before posting. Cross posting between different comp.os.linux.* groups is rarely a good idea.

There may well be Linux groups local to your institution or area--check there first.

See also "How To Get Information without Usenet Access."

Other regional and local newsgroups also exist--you may find the traffic more manageable there. The French Linux newsgroup is fr.comp.os.linux. In Germany there is de.comp.os.linux.*. In Australia, try aus.computers.linux. In Croatia there is hr.comp.linux. In Italy, there is it.comp.linux.

A search of http://groups.google.com/ can provide an up-to-date list of News groups.
[Axel Boldt, Robert Kiesling]

Table of Contents 2

2.5 What Other FAQ's and Documentation Are There for Linux?

There are a number of special interest FAQ's on different subjects related to system administration and use, and also on miscellaneous topics like Flying Saucer Attacks (the music) and support for recovering sysadmins.

The official Usenet FAQ archives are: ftp://rtfm.mit.edu/pub/usenet/.

The Internet FAQ Consortium provides a searchable archive at: http://www.faqs.org/. The site also maintains a current archive of Internet Request For Comment (RFC), Best Current Practices (BCP), and For Your Information (FYI) documents.

Here are some FAQ's and documents that might be especially useful, and their network addresses:

  * A FAQ for new users:
    http://homes.arealcity.com/swietanowski/LinuxFAQ/.
  * AfterStep FAQ:
    http://www.linuxinfor.com/en/astepfaq/AfterStep-FAQ.html.
  * BASH Frequently Asked Questions: ftp://ftp.cwru.edu/pug/bash/FAQ/.
  * de.comp.os.unix.linux.infos - FAQ: http://www.dcoul.de/.
  * Frequently Asked Questions about Open Source:
    http://www.opensource.org/faq.html.
  * Ftape-FAQ: http://www.linuxinfor.com/en/ftapefaq/Ftape-FAQ.html.
  * GNU Emacs: http://www.lerner.co.il/emacs/faq-body.shtml.
  * GNU Linux in Science and Engineering:
    http://www.comsoc.org/vancouver/scieng.html.
  * GNU Troff (groff) Info: http://www.cs.pdx.edu/~trent/gnu/groff/.
  * Gnus 5.x: http://www.ccs.neu.edu/software/contrib/gnus/.
  * KDE FAQ: http://www.kde.org/faq.html.
  * GNU General Public License FAQ:
    http://www.gnu.org/copyleft/gpl-faq.html.
  * Linux PPP FAQ: http://www.linuxinfor.com/en/pppfaq/PPP-FAQ.html.
  * Linux-Raid FAQ: http://www.linuxinfor.com/en/raidfaq/index.html.
  * List of Periodic Information Postings:
    ftp://rtfm.mit.edu/pub/usenet/news.answers/periodic-postings/.
  * News.newusers.announce FAQ http://web.presby.edu/~nnqadmin/nan/.
  * Online Linux Resources: http://www.linuxinfor.com/en/docfaq.htm.
  * O'Reilly & Associates Openbook Project:
    http://www.oreilly.com/openbook/.
  * Sendmail: http://www.sendmail.org/faq/.
  * Sendmail: Installation and Operation Guide: Formatted and me
    source versions are in the doc/ subdirectory of Sendmail source
    code distributions. http://www.sendmail.org/.
  * Technical FAQ for Linux Users:
    http://www-106.ibm.com/developerworks/library/l-faq/?n-l-7261.
  * Web Internet Search Engine: http://www.infobasic.com/pagefaq.html
  * Wu-ftpd: http://www.wu-ftpd.org/man/ (really a collection of man
    pages), with HOWTO's at: http://www.wu-ftpd.org/HOWTO/
  * XTERM--Frequently Asked Questions.
    http://dickey.his.com/xterm/xterm.faq.html.
Table of Contents 2

2.6 Where Are the Linux FTP Archives?

There are three main archive sites for Linux:

  * ftp://ftp.funet.fi/pub/OS/Linux/ (Finland).
  * ftp://metalab.unc.edu/pub/Linux/. Recently renamed to
    http://ibiblio.org/pub/linux/ with a nice WWW interface. (US).
  * ftp://tsx-11.mit.edu/pub/linux/ (US).

The best place to get the Linux kernel is ftp://ftp.kernel.org/pub/linux/kernel/. Linus Torvalds uploads the most recent kernel versions to this site.

Of the U.S. distributions, Debian GNU/Linux is available at ftp://ftp.debian.org/pub/debian/. Red Hat Linux's home site is ftp://ftp.redhat.com/, and Linux Slackware's is ftp://ftp.freesoftware.com/.

The Small Linux distribution, which can run in 2 MB of RAM, is located at http://smalllinux.netpedia.net/.

The contents of these sites is mirrored (copied, usually approximately daily) by a number of other sites. Please use a site close to you--it will be faster for you and easier on the network.

  * ftp://ftp.sun.ac.za/pub/linux/sunsite/ (South Africa)
  * ftp://ftp.is.co.za/linux/sunsite/ (South Africa).
  * ftp://ftp.cs.cuhk.hk/pub/Linux/ (Hong Kong).
  * ftp://sunsite.ust.hk/pub/Linux/ (Hong Kong).
  * ftp://ftp.spin.ad.jp/pub/linux/ (Japan).
  * ftp://ftp.nuri.net/pub/Linux/ (Korea).
  * ftp://ftp.jaring.my/pub/Linux/ (Malaysia).
  * ftp://ftp.nus.sg/pub/unix/Linux/ (Singapore).
  * ftp://ftp.nectec.or.th/pub/mirrors/linux/ (Thailand).
  * ftp://planetmirror.com/pub/linux (Australia). (Also take a look at
    http://planetmirror.com/archives.php.)
  * ftp://ftp.monash.edu.au/pub/linux/ (Australia).
  * ftp://ftp.univie.ac.at/systems/linux/sunsite/ (Austria).
  * ftp://ftp.fi.muni.cz/pub/UNIX/linux/ (Czech Republic).
  * ftp://ftp.funet.fi/pub/Linux/sunsite/ (Finland).
  * ftp://ftp.univ-angers.fr/pub/Linux/ (France).
  * ftp://ftp.iut-bm.univ-fcomte.fr/ (France).
  * ftp://ftp.ibp.fr/pub/linux/sunsite/ (France)
  * ftp://ftp.loria.fr/pub/linux/sunsite/ (France).
  * ftp://ftp.dfv.rwth-aachen.de/pub/linux/sunsite/ (Germany).
  * ftp://ftp.germany.eu.net/pub/os/Linux/Mirror.SunSITE/(Germany).
  * ftp://ftp.tu-dresden.de/pub/Linux/sunsite/ (Germany).
  * ftp://ftp.uni-erlangen.de/pub/Linux/MIRROR.sunsite/ (Germany).
  * ftp://ftp.gwdg.de/pub/linux/mirrors/sunsite/ (Germany).
  * ftp.rz.uni-karlsruhe.de/pub/linux/mirror.sunsite/ (Germany).
  * ftp://ftp.ba-mannheim.de/pub/linux/mirror.sunsite/ (Germany).
  * ftp://ftp.uni-paderborn.de/pub/Mirrors/sunsite.unc.edu/(Germany).
  * ftp://ftp.uni-rostock.de/Linux/sunsite/ (Germany).
  * ftp.rus.uni-stuttgart.de/pub/unix/systems/linux/MIRROR.sunsite/(Germany).
  * ftp://ftp.uni-tuebingen.de/pub/linux/Mirror.sunsite/ (Germany).
  * ftp://ftp.kfki.hu/pub/linux/(Hungary).
  * ftp://linux.italnet.it/pub/Linux/(Italy).
  * ftp://ftp.unina.it/pub/linux/sunsite/ (Italy).
  * ftp://giotto.unipd.it/pub/unix/Linux/ (Italy).
  * ftp://cnuce-arch.cnr.it/pub/Linux/ (Italy).
  * ftp://ftp.flashnet.it/mirror2/metalab.unc.edu/ (Italy).
  * ftp://ftp.nijenrode.nl/pub/linux/ (Netherlands).
  * ftp://ftp.LeidenUniv.nl/pub/linux/sunsite/ (Netherlands).
  * ftp://ftp.nvg.unit.no/pub/linux/sunsite/ (Norway).
  * ftp://sunsite.icm.edu.pl/pub/Linux/metalab.unc.edu/ (Poland).
  * ftp://ftp.rediris.es/software/os/linux/sunsite/ (Spain).
  * ftp://sunsite.rediris.es/software/linux/ (Spain).
  * ftp://ftp.cs.us.es/pub/Linux/sunsite-mirror/ (Spain).
  * ftp://ftp.etse.urv.es/pub/mirror/linux/ (Spain).
  * ftp://tp.etsimo.uniovi.es/pub/linux/ (Spain).
  * ftp://ftp.luna.gui.es/pub/linux.new/ (Spain).
  * ftp://ftp.metu.edu.tr/pub/linux/sunsite/ (Turkey).
  * ftp://unix.hensa.ac.uk/mirrors/sunsite/pub/Linux/ (UK).
  * ftp.maths.warwick.ac.uk/mirrors/linux/sunsite.unc-mirror/(UK).
  * ftp://ftp.idiscover.co.uk/pub/Linux/sunsite.unc-mirror/(UK).
  * ftp://sunsite.doc.ic.ac.uk/packages/linux/sunsite.unc-mirror/(UK).
  * ftp://ftp.io.org/pub/mirrors/linux/sunsite/ (Canada).
  * ftp://ftp.cc.gatech.edu/pub/linux/ (US).
  * ftp://ftp.freesoftware.com/pub/linux/sunsite/ (US).
  * ftp://ftp.siriuscc.com/pub/Linux/Sunsite/ (US).
  * ftp://ftp.engr.uark.edu/pub/linux/sunsite/ (US).
  * ftp://ftp.infomagic.com/pub/mirrors/linux/sunsite/ (US).
  * ftp://linux.if.usp.br/pub/mirror/metalab.unc.edu/pub/Linux/(Brazil).
  * ftp://farofa.ime.usp.br/pub/linux/ (Brazil).

Please send updates and corrections to this list to the Linux FAQ the other "source" sites, and some have material not available on the "source" sites.

Table of Contents 2

2.7 How To Get Linux without FTP Access

The easiest thing is probably to find a friend with FTP access. If there is a Linux user's group near you, they may be able to help.

If you have a reasonably good email connection, you could try the FTP-by-mail servers at ftpmail@ftp.sunet.se, or ftpmail@ftp.uni-stuttgart.de.

Linux is also available via traditional mail on CD-ROM. The file ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/Installation-HOWTO, and the file ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/Distribution-HOWTO contain information on these distributions.

Table of Contents 2

2.8 How To Get Information without Usenet Access

A digest of comp.os.linux.announce is available by mailing the word "subscribe" (without the quotes) as the body of a message to linux-announce-REQUEST@news-digests.mit.edu. Subscribing to this list is a good idea, as it carries important information and documentation about Linux.

Please remember to use the *-request addresses for your subscribe and unsubscribe messages; mail to the other address is posted to the news group.

Table of Contents 2

2.9 What Mailing Lists Are There?

The Linux developers now mainly use the Majordomo server at majordomo@vger.redhat.com. Send a message with the word "lists" (without the quotes) in the body to get a list of lists there. Add a line with the word, "help," to get the standard Majordomo help file that lists instructions for subscribing and unsubscribing to the lists.

Currently, the kernel list is archived at: http://www.uwsg.indiana.edu/hypermail/linux/kernel/, and http://www.lib.uaa.alaska.edu/linux-kernel/archive/

Please do not post off-topic material to the mailing lists. Most of them are used by Linux developers to talk about technical issues and future developments. They are not intended for new users' questions, advertisements, or public postings that are not directly related to the mailing list's subject matter. Comp.os.linux.announce is the place for all public announcements. This is a common Internet policy. If you don't observe this guideline, there's a good chance that you'll be flamed.

There is a linux-newbie list where, "no question is too stupid." Unfortunately, it seems that few experienced users read that list, and it has very low volume.

There are numerous Linux related mailing lists at http://www.onelist.com/. Go to the categories page and choose "Linux." There are also mailing list subscription links at: http://oslab.snu.ac.kr/~djshin/linux/mail-list/.

The Mailing Lists Available in Usenet page is: http://paml.net/. The list information is also on: ftp://rtfm.mit.edu/, and is posted to the groups: news.announce.newgroups, news.lists, and news.groups, among others.

Table of Contents 2

2.10 Where Are Linux Legal Issues Discussed?

On the linux-legal mailing list, of course. You can subscribe to it, as with many of the other Linux related lists, by sending a message with the word "help" in the body of the message to majordomo@vger.redhat.com.

Table of Contents 2

2.11 Sources of Information for Unmaintained Free Software Projects

There are Web pages at: http://unmaintained.sourceforge.net, and: http://www.orphansource.org/.

Please try to contact the original author(s) via e-mail, or the person who listed the software as unmaintained, before even thinking to place a license on the package.

Table of Contents 2

2.12 Are the News Groups Archived Anywhere?

The Usenet Linux news groups are archived at http://groups.google.com/.

ftp://metalab.unc.edu/pub/Linux/docs/linux-announce.archive contains archives of comp.os.linux.announce. These are mirrored from ftp://src.doc.ic.ac.uk/usenet/, which also archives comp.os.linux, comp.os.linux.development.apps, and comp.os.linux.development.system.

Table of Contents 2

2.13 Where To Find Information About Security Related Issues

There's a page of Linux related security information at: http://www.linuxsecurity.com/.

Another site is: http://www.rootshell.com/, which has information about Internet security and privacy issues.

For information about the Weekly Linux Security Digest email newsletter and numerous security related databases, look at http://securityportal.com/.

Table of Contents 2

2.14. Where To Find Linux System Specifications

As a start, look at the Linux Standards Base, http://www.linuxbase.org/. The site contains information about test software, file system organization, and shared library naming conventions.

Table of Contents 2
3. Compatibility with Other Operating Systems

3.1 Can Linux Use the Same Hard Drive as MS-DOS? OS/2? 386BSD? Win95?

Yes. Linux uses the standard MS-DOS partitioning scheme, so it can share your disk with other operating systems.

Linux has loadable kernel modules for (presumably) all versions of Microsoft FAT and VFAT file systems, including Windows 2000 and WindowsMe. In a correctly configured system, they should load automatically when the partitions are mounted.

Note, however, that many other operating systems may not be exactly compatible. DOS's FDISK.EXE and FORMAT.EXE, for example, can overwrite data in a Linux partition, because they sometimes incorrectly use partition data from the partition's boot sector rather than the partition table.

In order to prevent programs from doing this, it is a good idea to zero out--under Linux--the start of a partition you created, before you use MS-DOS--or whatever--to format it. Type:

   $ dd if=/dev/zero of=/dev/hdXY bs=512 count=1

where hdXY is the relevant partition; e.g., /dev/hda1 for the first partition of the first (IDE) disk.

Linux can read and write the files on your DOS and OS/2 FAT partitions and floppies using either the DOS file system type built into the kernel or mtools. There is kernel support for the VFAT file system used by Windows 9x and Windows NT.

There is reportedly a GPL'd OS/2 device driver that will read and write Linux ext2 partitions.

For information about FAT32 partition support, see http://bmrc.berkeley.edu/people/chaffee/fat32.html.

See, ("What Software does Linux Support?") for details and status of the emulators for DOS, MS Windows, and System V programs.

See also, "Can Linux access Amiga file systems? ", "Can Linux access Macintosh file systems? ", "Can Linux access BSD, SysV, etc., UFS? ", and "Can Linux access SMB file systems? "

There are said to be NTFS drivers under development, which should support compression as a standard feature.

Table of Contents 3

3.2 How To Access Files on a MS-DOS Partition or Floppy

Use the DOS file system, type, for example:

$ mkdir /dos
$ mount -t msdos -o conv=text,umask=022,uid=100,gid=100 /dev/hda3 /dos

If it's a floppy, don't forget to umount it before ejecting it!

You can use the conv=text/binary/auto, umask=nnn, uid=nnn, and gid=nnn options to control the automatic line-ending conversion, permissions and ownerships of the files in the DOS file system as they appear under Linux. If you mount your DOS file system by putting it in your /etc/fstab, you can record the options (comma-separated) there, instead of defaults.

Alternatively, you can use mtools, available in both binary and source form on the FTP sites. ("Where Are the Linux FTP Archives?")

A kernel patch (known as the fd-patches) is available which allows floppies with nonstandard numbers of tracks and/or sectors to be used; this patch is included in the 1.1 alpha testing kernel series.

Table of Contents 3

3.3 Does Linux Support Compressed Ext2 File Systems?

The ext2compr project provides a kernel patch Information about them is located at http://e2ompr.memalpha.cx/e2compr/.

There is also a Web site for the e2compr patches. The code is still experimental and consists of patches for the 2.0 and 2.1 kernels. For more information about the project, including the latest patches, and the address of the mailing list, look up the URL at http://debs.fuller.edu/e2compr/.
[Roderich Schupp, Peter Moulder]

zlibc is a program that allows existing applications to read compressed (GNU gzip'ed) files as if they were not compressed. Look at ftp://metalab.unc.edu/pub/Linux/libs/. The author is Alain Knaff.

There is also a compressing block device driver, "DouBle," by Jean-Marc Verbavatz, which can provide on-the-fly disk compression in the kernel. The source-only distribution is located at ftp://metalab.unc.edu/pub/Linux/patches/diskdrives/. This driver compresses inodes and directory information as well as files, so any corruption of the file system is likely to be serious.

There is also a package called tcx (Transparently Compressed Executables), which allows you to keep infrequently used executables compressed and only uncompress them temporarily when in use. It is located at ftp://metalab.unc.edu/pub/Linux/utils/compress/.

Table of Contents 3

3.4 Can Linux Use Stacked/DBLSPC/Etc. DOS Drives?

Until recently, not very easily. You can access DOS 6.X volumes from the DOS emulator ("What software does Linux support? "), but it's harder than accessing a normal DOS volume via the DOS kernel option, a module, or mtools.

There is a recently added package, dmsdos, that reads and writes compressed file systems like DoubleSpace/DriveSpace in MS-DOS 6.x and Win95, as well as Stacker versions 3 and 4. It is a loadable kernel module. Look at ftp://metalab.unc.edu/pub/Linux/system/filesystems/dosfs/.

Table of Contents 3

3.5 Can Linux Access OS/2 HPFS Partitions?

Yes, but Linux access to HPFS partitions is read-only. HPFS file system access is available as an option when compiling the kernel or as a module. See the Documentation/filesystems/hpfs.txt file in the kernel source distribution. ("How To Upgrade/Recompile a Kernel.") Then you can mount HPFS partition, using, for example:

$ mkdir /hpfs
$ mount -t hpfs /dev/hda5 /hpfs
Table of Contents 3

3.6 Can Linux Access Amiga File Systems?

The Linux kernel has support for the Amiga Fast File System (AFFS) version 1.3 and later, both as a compile-time option and as a module. The file Documentation/filesystems/affs.txt in the Linux kernel source distribution has more information.

See ("How To Upgrade/Recompile a Kernel.")

Linux supports AFFS hard-drive partitions only. Floppy access is not supported due to incompatibilities between Amiga floppy controllers and PC and workstation controllers. The AFFS driver can also mount disk partitions used by the Un*x Amiga Emulator, by Bernd Schmidt.

Table of Contents 3

3.7 Can Linux Access BSD, SysV, Etc. UFS?

Recent kernels can mount (read only) the UFS file system used by System V; Coherent; Xenix; BSD; and derivatives like SunOS, FreeBSD, NetBSD, and NeXTStep. UFS support is available as a kernel compile-time option and a module.

See, ("How To Upgrade/Recompile a Kernel.")

Table of Contents 3

3.8 Can Linux Access SMB File Systems?

Linux supports read/write access of Windows for Workgroups and Windows NT SMB volumes. See the file Documentation/filesystems/smbfs.txt of the Linux kernel source distribution, and ("How To Upgrade/Recompile a Kernel.")

There is also a suite of programs called Samba which provide support for WfW networked file systems (provided they're for TCP/IP). Information is available in the README file at metalab.unc.edu/pub/Linux/system/network/samba/.

The SMB Web site is http://www.samba.org/, and there is also a Web site at samba.anu.edu.au/samba/.

Table of Contents 3

3.9 Can Linux Access Macintosh File Systems?

There is a set of user-level programs that read and write the older Macintosh Hierarchical File System (HFS). It is available at metalab.unc.edu/pub/Linux/utils/disk-management/.

Access to the newer, HFS+ file systems is still under development.

Table of Contents 3

3.10 Can Linux Run Microsoft Windows Programs?

WINE, a MS Windows emulator for Linux, is still not ready for general distribution. If you want to contribute to its development, look for the status reports in the comp.emulators.ms-windows.wine newsgroup.

There is also a FAQ, compiled by P. David Gardner, at ftp://metalab.unc.edu/pub/Linux/docs/faqs/Wine-FAQ/.

In the meantime, if you need to run MS Windows programs, the best bet--seriously--is to reboot. LILO, the Linux boot loader, can boot one of several operating systems from a menu. See the LILO documentation for details.

Also, LOADLIN.EXE (a DOS program to load a Linux, or other OS, kernel is one way to make Linux co-exist with DOS. LOADLIN.EXE is particularly handy when you want to install Linux on a 3rd or 4th drive on a system (or when you're adding a SCSI drive to a system with an existing IDE).

In these cases, it is common for LILO's boot loader to be unable to find or load the kernel on the "other" drive. So you just create a C:\LINUX directory (or whatever), put LOADLIN.EXE in it with a copy of your kernel, and use that.

LOADLIN.EXE is a VCPI compliant program. Win95 will want to, "shutdown into DOS mode," to run it (as it would with certain other DOS protected-mode programs).

Earlier versions of LOADLIN.EXE sometimes required a package called REALBIOS.COM, which required a boot procedure on an (almost) blank floppy to map the interrupt vectors (prior to the loading of any software drivers). (Current versions don't seem to ship with it, and don't seem to need it).
[Jim Dennis]

Table of Contents 3

3.11 Where Is Information about NFS Compatibility?

This information is partly taken from Nicolai Langfeldt's excellent NFS HOWTO, and is current as of 10/1/1999.

Most version 2.2.x kernels need a set of patches to install the knfsd subsystem, maintained by H.J. Lu, to communicate efficiently (if at all) with Sparc, IBM RS, and Alpha machines, and probably others. This package is actually a collection of patches to the kernel sources. Better support for non-Intel architectures is included in the 2.4 kernels.

There is also a user-space server. Although it lacks remote file locking, it is easier to install. It may be equally efficient.

In the Documentation/Changes of recent kernel distributions, there is a list of URL's for both the knfsd server and the user-space server.

There is a CVS server available for the kernel-space NFS subsystem, as well as a NFS WWW page at http://www.linuxnfs.sourceforge.org/, although the URL requires a password for access. The relevant URL's are listed in the README.nfs file at ftp://ftp.us.kernel.org/, and other kernel archive sites, along with login information. Patches are at ftp://ftp.varesearch.com/pub/kernel/latest/patches/.

The source archives of the user-space server and utilities currently reside on ftp://linux.mathematik.tu-darmstadt.de:/pub/linux/people/okir/.

In the case of older Solaris releases, the lack of statd or lockd on a client or server machine may cause incompatibility. On some versions of Solaris, statd can be used to exploit features of the automounter. Sun released a patch to correct this, but statd still needs to be started by root on such systems. On recent Solaris systems, refer to the information in /etc/dfs/dfstab and the share(1M) manual page to enable volume sharing. In addition, the rpcinfo program can tell you if statd or lockd are available on the local or remote machines.

The linux-kernel mailing list has on-and-off discussions of the status of the NFS subsystem, which appears to be changing rapidly.
[Nicolai Langfeldt, Robert Kiesling, Anders Hammarquist]

Table of Contents 3

3.12 Can Linux Use True Type Fonts?

Yes. There are a number of True Type font servers for the X Window System. One of them is xfsft. Its home page is http://www.dcs.ed.ac.uk/home/jec/programs/xfsft/. There are also instructions for configuration.

People have reported success with other True Type font servers. There are links from the xfsft Home Page to them as well.

You can also compile True Type Font support into your X server directly. Again, refer to the xfsft Home Page for details.

Table of Contents 3

3.13 Can Linux Boot from MS-DOS?

If LILO doesn't work, and if the machine has MS-DOS or Microsoft Windows, you may be left with a computer that won't boot. This can also happen on an upgrade to your Linux distribution. Re-installing LILO is the last thing that the installation does. So it is vitally important when installing or upgrading Linux on a dual boot machine, to have a MS-DOS or Windows rescue disk nearby so you can FDISK -MBR. Then you can go about using LOADLIN.EXE instead of LILO.

This config.sys file is one possible way to invoke LOADLIN.EXE and boot MS-DOS or Linux.

[menu]
menuitem=DOS, Dos Boot
menuitem=LINUX, Linux Boot

[LINUX]
shell=c:\redhat\loadlin.exe c:\redhat\autoboot\vmlinuz vga=5 root=/dev

[DOS]
STACKS = 0,0
rem all the other DOS drivers get loaded here.

This creates a menu where you can directly jump to LOADLIN.EXE before all of the MS-DOS drivers get loaded.

The paths and options are peculiar to one machine and should be intuitively obvious to the most casual observer. See the LOADLIN.EXE docs for options. They are the same as LILO, and options are just passed to the kernel, anyhow.
[Jim Harvey]

Table of Contents 3

3.14 How Can Linux Boot from OS/2's Boot Manager?

Create a partition using OS/2's FDISK.EXE (Not Linux's fdisk).
Format the partition under OS/2, either with FAT or HPFS. This is so that OS/2 knows about the partition being formatted. (This step is not necessary with OS/2 `warp' 3.0.)
Add the partition to the Boot Manager.
Boot Linux, and create a file system on the partition using mkfs -t ext2 or mke2fs. At this point you may, if you like, use Linux's fdisk to change the code of the new partition to type 83 (Linux Native)--this may help some automated installation scripts find the right partition to use.
Install Linux on the partition.
Install LILO on the Linux partition--NOT on the master boot record of the hard drive. This installs LILO as a second-stage boot loader on the Linux partition itself, to start up the kernel specified in the LILO configuration file. To do this, you should put boot = /dev/hda2 (where /dev/hda2 is the partition you want to boot from) in your /etc/lilo/config or /etc/lilo.config file.
Make sure that it is the Boot Manager partition that is marked active, so that you can use Boot Manager to choose what to boot.

There is a set of HOWTO's on the subject of multi-boot systems at the LDP Home Page, http://www.linuxdoc.org/.

Table of Contents 3
4. File Systems, Disks, and Drives

4.1 How To Get Linux to Work with a Disk

If your disk is an IDE or EIDE drive, you should read the file /usr/src/linux/drivers/block/README.ide (part of the Linux kernel source code). This README contains many helpful hints about IDE drives. Many modern IDE controllers do translation between `physical' cylinders/heads/sectors, and `logical' ones.

SCSI disks are accessed by linear block numbers. The BIOS invents some `logical' cylinder/head/sector fiction to support DOS.

Older IBM PC-compatible BIOS's will usually not be able to access partitions which extend beyond 1024 logical cylinders, and will make booting a Linux kernel from such partitions using LILO problematic at best.

You can still use such partitions for Linux or other operating systems that access the controller directly.

It's recommend that you create at least one Linux partition entirely under the 1024 logical cylinder limit, and boot from that. The other partitions will then be okay.

Also there seems to be a bit of trouble with the newer Ultra-DMA drives. I haven't gotten the straight scoop on them--but they are becoming a very common problem at the SVLUG installfests. When you can get 8 to 12 Gig drives for $200 to $300 it's no wonder.
[Jim Dennis]

Table of Contents 4

4.2 How To Undelete Files

In general, this is very hard to do on unices because of their multitasking nature. Undelete functionality for the ext2fs file system is being worked on, but don't hold your breath.

There are a number of packages available which instead provide new commands for deleting and copying which move deleted files into a `wastebasket' directory. The files can be recovered until cleaned out automatically by background processing.

The Midnight Commander file manager provides an undelete facility that uses Ext2 file system library functions and an undelete directory for each file system. Commercial distribution packages of MC may or may not have this feature enabled, so be sure to look in the source code distribution for instructions on how to enable the undelete feature.

Alternatively, you can search the raw disk device which holds the file system in question. This is hard work, and you will need to be logged in as root to do this. But it can be done. Run grep on the raw device; e.g.:

   grep -b 'bookmarks' /dev/hda

If the data has not been overwritten, you should be able to recover it with a text editor.
[Dave Cinege, Daniel Novotny]

Table of Contents 4

4.3 How To Make Backups

You can back up a directory hierarchy or complete file system to any media using GNU tar or cpio, the standard *nix tools for this purpose. tar seems to be the more commonly used program currently, and includes command line options to make compressed, incremental, and multi-volume backups. Complete information is contained in the documentation, which is in GNU Texinfo format.

The free program, Amanda, receives a lot of mentions on Usenet. Its home page is http://www.amanda.org/.

Several commercial backup utilities also exist. They are often included in commercial distributions.

Table of Contents 4

4.4 How To Resize a Partition (Non-Destructively)

Use the FIPS.EXE program, included with most Linux distributions,under MS-DOS.

GNU parted, a partition editor, is stable enough for non-guru, mere-mortal use with relative confidence. Source code for the latest version is at: ftp://ftp.gnu.org/pub/gnu/parted/. There's also a boot disk image for resizing root partitions and for running parted on non-Linux machines. The disk image may be easier for beginners. Building from source could require some extra configuration.

Parted also has tutorial-style, plain-text documentation for Linux and FAT (MS-DOS) file systems.

Also, some commercial distributions come with their own partitioning software, like Partition Magic.

Table of Contents 4

4.5 Is There a Defragmenter for Ext2fs?

Yes. There is defrag, a Linux file system defragmenter for ext2, Minix, and old-style ext file systems. It is available at ftp://metalab.unc.edu/pub/Linux/system/filesystems/defrag-0.70.tar.gz.

Users of the ext2 file system can probably do without defrag, because ext2 contains extra code to keep fragmentation reduced even in very full file systems.

Table of Contents 4

4.6 How To Create a File System on a Floppy

To format a 3.5-inch, high density floppy:

$ fdformat /dev/fd0H1440
$ mkfs -t ext2 -m 0 /dev/fd0H1440 1440

For a 5.25 inch floppy, use fd0h1200 and 1200 as appropriate. For the B: drive use fd1 instead of fd0.

The -m 0 option tells mkfs.ext2 not to reserve any space on the disk for the superuser--usually the last 10% is reserved for root.

The first command performs a low-level format. The second creates an empty file system. You can mount the floppy like a hard disk partition and simply cp and mv files, etc.

Device naming conventions generally are the same as for other unices. They can be found in Matt Welsh's Installation and Getting Started guide. Refer to ("Where Is the Documentation?") A more detailed and technical description is Linux Allocated Devices by H. Peter Anvin, hpa@zytor.com, which is included in LaTeX and ASCII form in the kernel source distribution (probably in /usr/src/kernel/Documentation/), as devices.tex and devices.txt.

Table of Contents 4

4.7 Does Linux Support Virtualized File Systems Like RAID?

The most recent Linux kernels support software RAID, and they will work with RAID disk controllers.

An automounter for NFS partitions is part of most Linux distributions.

In addition, several virtual file system projects exist. One of them, the Linux Logical Volume Manager, is located at http://linux.msede.com/lvm/.

Table of Contents 4

4.8 Does Linux Support File System Encryption?

Yes. One file system, ppdd, is archived at http://pweb.de.uu.net/flexsys.mtk/.

Table of Contents 4

4.9 Linux Prints Nasty Messages about Inodes, Blocks, and the Like.

You may have a corrupted file system, probably caused by not shutting Linux down properly before turning off the power or resetting. You need to use a recent shutdown program to do this--for example, the one included in the util-linux package, available on sunsite and tsx-11.

If you're lucky, the program fsck (or e2fsck or xfsck as appropriate if you don't have the automatic fsck front-end) will be able to repair your file system. If you're unlucky, the file system is trashed, and you'll have to re-initialize it with mkfs (or mke2fs, mkxfs, etc.), and restore from a backup.

NB: don't try to check a file system that's mounted read/write--this includes the root partition, if you don't see
VFS: mounted root ... read-only
at boot time.

Table of Contents 4

4.10 The Swap Area Isn't Working

When you boot (or enable swapping manually) you should see

   Adding Swap: NNNNk swap-space

If you don't see any messages at all you are probably missing

   swapon -av

(the command to enable swapping) in your /etc/rc.local or /etc/rc.d/* (the system startup scripts), or have forgotten to make the right entry in /etc/fstab:

   /dev/hda2       none       swap       sw

for example.
If you see:

   Unable to find swap-space signature

you have forgotten to run mkswap. See the manual page for details; it works much like mkfs.

Running, free in addition to showing free memory, should display:

             total       used       free
Swap:        10188       2960       7228

If typing "cat /proc/swaps" reveals only file or partition names, but no swap space information, then the swap file or partition needs re-initialization.

Use fdisk (as root) to determine which partition on a hard drive has been designated as the swap partition. The partition still needs to be initialized with mkswap before enabling it with swapon.
[Andy Jefferson, Steve Withers]

Table of Contents 4

4.11 How To Add Temporary Swap Space

In addition to a swap partition, Linux can also use a swap file. Some programs, like g++, can use huge amounts of virtual memory, requiring the temporary creation of extra space. To install an extra 64 MB of swap space, for example, use the following shell commands:

# dd if=/dev/zero of=/swap bs=1024 count=65535
# mkswap /swap
# swapon /swap

The count= argument to dd determines how big the swap file will be. In this example the swap file's name is /swap, but the name and location are, generally, arbitrary, depending only on the file system's available space and your having write permissions in the directory.

When you don't need the swap space any more, remove it with the following statements:

# swapoff /swap
# rm /swap

Take a look also at the Installation HOWTO and Installation & Getting Started for detailed instructions.

If that still doesn't provide enough swap space, refer to ("How To Have More Than 128Mb of Swap.")

Table of Contents 4

4.12 How To Remove LILO So the System Boots DOS Again?

The lilo program (not the complete LILO package), uses the command line option -u to uninstall the LILO boot loader. You have to supply the device name of the device you installed LILO on, for example:

   lilo -u /dev/hda

This rewrites the original, pre-LILO master boot record back to the first hard drive, from the boot record saved in /boot/boot.0300. If you installed LILO to a partition as a secondary boot loader, for example, /dev/hda1, lilo re-installs the original boot sector from the save file /boot/boot.0301. Refer to the lilo manual page for details. Thanks to Villy Kruse for reminding me to update this answer.

If you have an earlier version of LILO, you will have to use the DOS (MS-DOS 5.0 or later, or OS/2) FDISK /MBR (which is not documented). This will restore a standard MS-DOS Master Boot Record. If you have DR-DOS 6.0, go into FDISK.EXE in the normal way and then select the Re-write Master Boot Record option.

If you create a boot floppy during the Windows installation process, make sure that it contains the programs FDISK.EXE, FORMAT.COM, and SYS.COM, and use that to re-install MS-DOS on the hard disk.

If you don't have MS-DOS or DR-DOS, you need to have the boot sector that LILO saved when you first installed it. You did keep that file, didn't you? It's probably called boot.0301 or some such. Type:

   dd if=boot.0301 of=/dev/hda bs=445 count=1

(or /dev/sda if you're using a SCSI disk). This may also wipe out your partition table, so beware! If you're desperate, you could use

   dd if=/dev/zero of=/dev/hda bs=512 count=1

This will erase your partition table and boot sector completely: you can then reformat the disk using your favorite software. But this will render the contents of your disk inaccessible--you'll lose it all unless you're an expert.

Note that the DOS MBR boots whichever (single!) partition is flagged as "active." You may need to use fdisk to set and clear the active flags on partitions appropriately.

Table of Contents 4

4.13 Why Does fdformat Require Superuser Privileges?

The system call to format a floppy can only be done as root, regardless of the permissions of /dev/fd0*. If you want any user to be able to format a floppy, try getting the fdformat2 program. This works around the problems by being setuid to root.

Table of Contents 4

4.14 The System Checks the Ext2fs Partitions Each Reboot

Refer to ("EXT2-fs: warning: mounting unchecked file system.)

Table of Contents 4

4.15 Root File System Is Read-Only

Remount it. If /etc/fstab is correct, you can simply type:

   mount -n -o remount /

If /etc/fstab is wrong, you must give the device name and possibly the type, too: e.g.

   mount -n -o remount -t ext2 /dev/hda2 /

To understand how you got into this state, see, ("EXT2-fs: warning: mounting unchecked file system.")

Table of Contents 4

4.16 What Is /proc/kcore?

None of the files in /proc are really there--they're all, "pretend," files made up by the kernel, to give you information about the system and don't take up any hard disk space.

/proc/kcore is like an "alias" for the memory in your computer. Its size is the same as the amount of RAM you have, and if you read it as a file, the kernel does memory reads.

Table of Contents 4

4.17 The AHA1542C Doesn't Work with Linux

The option to allow disks with more than 1024 cylinders, which the AHA1542C card can recognize, is only required as a workaround for a PC-compatible BIOS misfeature and should be turned `off' under Linux. For older Linux kernels you need to turn off most of the `advanced BIOS' options--all but the one about scanning the bus for bootable devices.

Table of Contents 4

4.18 Where Is the Journalling File System on the Net?

The journalling file system, named Reiserfs has just been released from testing. It is said to make Linux even faster than Linux with the Ext2 file system installed. Complete information is available at http://devlinux.org/namesys/.

Table of Contents 4