Linux Frequently Asked Questions with Answers

This is the list of Frequently Asked Questions for Linux, the free operating system kernel that runs on many modern computer systems. The kernel source code documentation says that Linux ``aims for POSIX compliance.'' Linux uses mostly free, GNU system utilities and application software, although commercial programs are available also. Originally written for 386/486/586 Intel/ISA bus machines, Linux versions exist for nearly every hardware platform in existence that is capable of running it. (Please refer to the question, ``What Is Linux?'' below.) This FAQ is meant to be read in conjunction with the Linux Documentation Project's HOWTO series. (``Where Can I Get Linux Material by FTP?'' and, ``Where Can I Get the HOWTO's and Other Documentation?'') The INFO-SHEET and META-FAQ also list sources of Linux information. Please read them, and, ``You Still Haven't Answered My Question!'' before posting to a Usenet news group. You can also get Postscript, HTML, and SGML versions of this document. (``Formats in Which This FAQ Is Available.'')

Table of Contents
1. Introduction and General Information
1.1. What Is Linux?
1.2. Where Do I Start?
1.3. What Software Does Linux Support?
1.4. Where Can I Find Application XXX? (Was: Has Anyone Ported/Compiled/Written XXX for Linux?)
1.5. Does Linux Run on My Computer? What Hardware Is Supported?
1.6. What Ports to Other Processors Are There?
1.7. How Much Hard Disk Space Does Linux Need?
1.8. How Much Memory Does Linux Need?
1.9. How Much Memory Can Linux Use?
1.10. Does Linux Support Universal System Bus Devices?
1.11. Is Linux Public Domain? Copyrighted?
1.12. Is Linux *nix?
2. Topics of Current Interest.
2.1. How Do I Cope with Anti-Linux FUD?
2.2. Should I Upgrade to the 2.4.0 Kernel? Now?
2.3. Should I Use the Red Hat 7.0 kgcc Compiler?
2.4. What Resources Are There for Linux DeCSS and Other Open Source DVD Software?
2.5. Where Is Information About Electronic Privacy Laws that Affect ISP's?
2.6. How Is the DocBook Version of the FAQ Produced?
3. Network Sources and Resources
3.1. Where Can I Get the Latest Kernel Version?
3.2. Where Can I Get the HOWTO's and Other Documentation?
3.3. Where Should I Look on the World Wide Web for Linux Stuff?
3.4. What News Groups Are There for Linux?
3.5. What Other FAQ's and Documentation Are There for Linux?
3.6. Where Can I Get Linux Material by FTP?
3.7. I Don't Have FTP Access. Where Do I Get Linux?
3.8. I Don't Have Usenet Access. Where Do I Get Information?
3.9. What Mailing Lists Are There?
3.10. Where Are Linux Legal Issues Discussed?
3.11. Where Can I Find Out About Unmaintained Free Software?
3.12. Are the News Groups Archived Anywhere?
3.13. Where Can I Find Out About Security Related Issues?
3.14. Where Can I Find Linux System Specifications?
4. Compatibility with Other Operating Systems
4.1. Can Linux Share My Disk with DOS? OS/2? 386BSD? Win95?
4.2. How Do I Access Files on My DOS Partition or Floppy?
4.3. Does Linux Support Compressed Ext2 File Systems?
4.4. Can I Use My Stacked/DBLSPC/Etc. DOS Drive?
4.5. Can I Access OS/2 HPFS Partitions from Linux?
4.6. Can Linux Access Amiga File Systems?
4.7. Can Linux Access BSD, SysV, Etc. UFS?
4.8. Can Linux Access SMB File Systems?
4.9. Can Linux Access Macintosh File Systems?
4.10. Can I Run Microsoft Windows Programs under Linux?
4.11. Where Can I Get Information about NFS Compatibility?
4.12. Can I Use True Type Fonts with Linux?
4.13. How Can I Boot Linux from MS-DOS?
4.14. How Can I Boot Linux from OS/2's Boot Manager?
5. File Systems, Disks, and Drives
5.1. How Can I Get Linux to Work with My Disk?
5.2. How Can I Undelete Files?
5.3. How Do I Make Backups?
5.4. How Do I Resize a Partition (Non-Destructively)?
5.5. Is There a Defragmenter for Ext2fs, Etc.?
5.6. How Do I Format and Create a File System on a Floppy?
5.7. Does Linux Support Virtualized File Systems Like RAID?
5.8. Does Linux Support File System Encryption?
5.9. I Get Nasty Messages about Inodes, Blocks, and the Like.
5.10. My Swap Area Isn't Working.
5.11. How Do I Add Temporary Swap Space?
5.12. How Do I Remove LILO So My System Boots DOS Again?
5.13. Why Can't I Use fdformat Except as Root?
5.14. The System Checks the Ext2fs Partitions Each Reboot.
5.15. My Root File System Is Read-Only!
5.16. I Have a Huge /proc/kcore! Can I Delete It?
5.17. The AHA1542C Doesn't Work with Linux.
5.18. Where Do I Find the Journalling File System?
6. Porting, Compiling and Obtaining Programs
6.1. How Do I Compile Programs?
6.2. How Do I Install GNU Software?
6.3. Where Do I Get Java?
6.4. How Do I Port XXX to Linux?
6.5. What Is ld.so and Where Do I Get It?
6.6. How Do I Upgrade the Libraries without Trashing My System?
6.7. Can I Use Code or a Compiler Compiled for a 486 on My 386?
6.8. What Does ``gcc -O6'' Do?
6.9. Where Are linux/*.h and asm/*.h?
6.10. I Get Errors when I Try to Compile the Kernel.
6.11. How Do I Make a Shared Library?
6.12. My Executables Are (Very) Large.
6.13. Does Linux Support Threads or Lightweight Processes?
6.14. Where Can I Get lint for Linux?
6.15. Where Can I Find Kermit for Linux?
6.16. I Want to Use Linux with My Cable Modem.
6.17. Is There an ICQ Program That Runs under Linux?
7. Solutions to Common Miscellaneous Problems
7.1. File Transfers over PPP Connections Seem to Hang.
7.2. Free Dumps Core.
7.3. Netscape Crashes Frequently
7.4. FTP or Telnet Server Won't Allow Logins.
7.5. How Do I Keep Track of All My Bookmarks in Netscape?
7.6. The Computer Has the Wrong Time.
7.7. Setuid Scripts Don't Seem to Work.
7.8. Free Memory as Reported by free Keeps Shrinking.
7.9. When I Add More Memory, the System Slows to a Crawl.
7.10. Some Programs (E.g. xdm) Won't Let Me Log in.
7.11. Some Programs Let Me Log In with No Password.
7.12. My Machine Runs Very Slowly when I Run GCC / X / ...
7.13. I Can Only Log In as Root.
7.14. My Screen Is All Full of Weird Characters Instead of Letters.
7.15. I Have Screwed Up My System and Can't Log In to Fix It.
7.16. I Forgot the root Password.
7.17. I've Discovered a Huge Security Hole in rm!
7.18. lpr and/or lpd Don't Work.
7.19. Timestamps on Files on MS-DOS Partitions Are Set Incorrectly
7.20. How Do I Get LILO to Boot the Kernel Image?
7.21. How Do I Make Sure My System Boots after Re-Installing the Operating System?
7.22. I Upgraded the Kernel and Now My PCMCIA Card Doesn't Work.
7.23. How Do I Remove (Or Change) the Colors in the ls Display?
7.24. Why Won't a Program Work in the Current Directory?
8. How Do I Do This or Find Out That...
8.1. How Do I Know If My Notebook Runs Linux?
8.2. How Do I Install Linux Using FTP?
8.3. How Do I Resume an Interrupted Download?
8.4. How Do I Configure Linux at Boot Time?
8.5. How Do I View Manual Pages without man or groff?
8.6. How Can I Get Scrollback in Text Mode?
8.7. How Do I Get E-mail to Work?
8.8. How Do I Prevent Sendmail from Pausing for Up to a Minute at Each Command?
8.9. How Do I Switch Virtual Consoles? How Do I Enable Them?
8.10. How Do I Set the Time Zone?
8.11. How Do I Get Dial-up PPP to Work?
8.12. What Version of Linux and What Machine Name Am I Using?
8.13. What Is a ``core'' File?
8.14. How Can I Enable or Disable Core Dumps?
8.15. How Do I Upgrade/Recompile My Kernel?
8.16. Can I Have More than 3 Serial Ports by Sharing Interrupts?
8.17. How Do I Configure Emacs to Start with My Default Settings?
8.18. How Do I Make a Rescue Floppy?
8.19. How Do I Remap My Keyboard to UK, French, Etc.?
8.20. How Do I Get NUM LOCK to Default to On?
8.21. How Do I Set (Or Reset) My Initial Terminal Colors?
8.22. How Can I Have More Than 128Mb of Swap?
9. Miscellaneous Information and Questions Answered
9.1. How Do I Program XYZ Under Linux?
9.2. What's All This about ELF? glibc?
9.3. How Do I Determine What Packages Are Installed on My System?
9.4. What Is a .gz File? And a .tgz? And .bz2? And... ?
9.5. What Does VFS Stand For?
9.6. What is a BogoMip?
9.7. What Online/Free Periodicals Exist for Linux?
9.8. How Many People Use Linux?
9.9. How Many People Use Linux? (Redux.)
9.10. What Is the Best (Distribution|SCSI Card|Editor|CD-ROM Drive|....)
9.11. How Should I Pronounce Linux?
10. Frequently Encountered Error Messages
10.1. Modprobe Can't Locate Module, XXX, and Similar Messages.
10.2. Unknown Terminal Type ``linux'' and Similar.
10.3. INET: Warning: old style ioctl... called!
10.4. ld: unrecognized option '-m486'
10.5. GCC Says, ``Internal compiler error.''
10.6. Make Says, ``Error 139.''
10.7. Shell-Init: Permission Denied when I Log In.
10.8. No Utmp Entry. You Must Exec ... when Logging In.
10.9. Warning--bdflush Not Running.
10.10. Warning: obsolete routing request made.
10.11. EXT2-fs: warning: mounting unchecked file system.
10.12. EXT2-fs warning: maximal count reached.
10.13. EXT2-fs warning: checktime reached.
10.14. df Says, ``Cannot read table of mounted file systems.''
10.15. fdisk Says, ``Partition X has different physical/logical...''
10.16. fdisk: Partition 1 does not start on cylinder boundary.
10.17. fdisk Says Partition n Has an Odd Number of Sectors.
10.18. A Mtools Utility Says It Cannot Initialize Drive XYZ.
10.19. At the Start of Booting: Memory tight
10.20. My Syslog says, ``end_request: I/O error, ....''
10.21. ``You don't exist. Go away.''
10.22. ``Operation not permitted.''
10.23. programname: error in loading shared libraries: lib xxx..so. x: cannot open shared object file: No such file or directory.
10.24. ``init: Id "x" respawning too fast: disabled for 5 minutes.''
10.25. FTP server says: ``421 service not available, remote server has closed connection.''
11. The X Window System
11.1. Does Linux Support X?
11.2. How Do I Get the X Window System to Work?
11.3. Where Can I Get a Ready-Made XF86Config for My System?
11.4. What Desktop Environments Run on Linux?
11.5. xterm Logins Show Up Strangely in who, finger.
12. How to Get Further Assistance
12.1. You Still Haven't Answered My Question!
12.2. What to Put in a Request for Help.
12.3. I Want to Mail Someone about My Problem.
13. Acknowledgments and Administrivia
13.1. Feedback Is Invited.
13.2. Formats in Which This FAQ Is Available.
13.3. Authorship and Acknowledgments.
13.4. Disclaimer and Copyright.
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  Introduction and General Information