Linux Frequently Asked Questions with Answers

Robert Kiesling, kiesling@ix.netcom.com

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 Does Linux run on my computer? What hardware is supported?
• 1.5 What ports to other processors are there?
• 1.6 How much hard disk space does Linux need?
• 1.7 How much memory does Linux need?
• 1.8 How much memory can Linux use?
• 1.9 Is Linux public domain? Copyrighted?

2. Network sources and resources.

• 2.1 Where can I get the HOWTO's and other documentation?
• 2.2 Where should I look on the World Wide Web for Linux stuff?
• 2.3 What newsgroups are there for Linux?
• 2.4 Where can I find out about Linux and the Millennium (Y2K) bug?
• 2.5 Where can I get Linux material by FTP?
• 2.6 I don't have FTP access. Where do I get Linux?
• 2.7 I don't have Usenet access. Where do I get information?
• 2.8 What mailing lists are there?
• 2.9 Are the newsgroups archived anywhere?

3. Compatibility with other operating systems.

• 3.1 Can Linux share my disk with DOS? OS/2? 386BSD? Win95?
• 3.2 How do I access files on my DOS partition or floppy?
• 3.3 Does Linux support compressed ext2 file systems?
• 3.4 Can I use my Stacked/DBLSPC/etc. DOS drive?
• 3.5 Can I access OS/2 HPFS partitions from Linux?
• 3.6 Can Linux access Amiga file systems?
• 3.7 Can Linux access BSD, SysV, etc. UFS?
• 3.8 Can Linux access SMB file systems?
• 3.9 Can Linux access Macintosh file systems?
• 3.10 Can I run Microsoft Windows programs under Linux?
• 3.11 How can I boot Linux from OS/2's Boot Manager?
• 3.12 How can I share a swap partition between Linux and MS Windows?

4. Linux's handling of file systems, disks, and drives

• 4.1 How can I get Linux to work with my disk?
• 4.2 How can I undelete files?
• 4.3 Is there a defragmenter for ext2fs etc.?
• 4.4 How do I format and create a file system on a floppy?
• 4.5 I get nasty messages about inodes, blocks, and the like.
• 4.6 My swap area isn't working.
• 4.7 How do I remove LILO so my system boots DOS again?
• 4.8 Why can't I use fdformat except as root?
• 4.9 My ext2fs partitions are checked each time I reboot.
• 4.10 My root file system is read-only!
• 4.11 I have a huge /proc/kcore! Can I delete it?
• 4.12 My AHA1542C doesn't work with Linux.

5. Porting, compiling and obtaining programs

• 5.1 How do I compile programs?
• 5.2 How do I port XXX to Linux?
• 5.3 What is ld.so and where do I get it?
• 5.4 How do I upgrade the libraries withough trashing my system?
• 5.5 Has anyone ported / compiled / written XXX for Linux?
• 5.6 Can I use code or a compiler compiled for a 486 on my 386?
• 5.7 What does gcc -O6 do?
• 5.8 Where are linux/*.h and asm/*.h?
• 5.9 I get errors when I try to compile the kernel.
• 5.10 How do I make a shared library?
• 5.11 My executables are (very) large.
• 5.12 Does Linux support threads or lightweight processes?
• 5.13 Where can I get `lint' for Linux?
• 5.14 Where can I find kermit for Linux?

6. Solutions to common miscellaneous problems.

• 6.1 free dumps core.
• 6.2 My clock is very wrong.
• 6.3 Setuid scripts don't seem to work.
• 6.4 Free memory as reported by free keeps shrinking.
• 6.5 When I add more memory, the system slows to a crawl.
• 6.6 Some programs (e.g. xdm) won't let me log in.
• 6.7 Some programs let me log in with no password.
• 6.8 My machine runs very slowly when I run GCC / X / ...
• 6.9 I can only log in as root.
• 6.10 My screen is all full of weird characters instead of letters.
• 6.11 I have screwed up my system and can't log in to fix it.
• 6.12 I've discovered a huge security hole in rm!
• 6.13 lpr(1) and/or lpd(8) don't work.
• 6.14 Timestamps on files on MS-DOS partitions are set incorrectly.
• 6.15 How do I get LILO to boot the vmlinux file?

7. How do I do this or find out that ... ?

• 7.1 How can I get scrollback in text mode?
• 7.2 How do I switch virtual consoles? How do I enable them?
• 7.3 How do I set the time zone?
• 7.4 What version of Linux and what machine name am I using?
• 7.5 How can I enable or disable core dumps?
• 7.6 How do I upgrade/recompile my kernel?
• 7.7 Can I have more than 3 serial ports by sharing interrupts?
• 7.8 How do I make a bootable floppy?
• 7.9 How do I remap my keyboard to UK, French, etc.?
• 7.10 How do I get NUM LOCK to default to on?
• 7.11 How do I set (or reset) my initial terminal colors?
• 7.12 How can I have more than 128Mb of swap?

8. Miscellaneous information and questions answered.

• 8.1 How do I program XYZ under Linux?
• 8.2 What's all this about ELF?
• 8.3 What is a .gz file ? And a .tgz ? And ... ?
• 8.4 What does VFS stand for?
• 8.5 What is a BogoMip?
• 8.6 What is the Linux Journal and where can I get it?
• 8.7 What online/free periodicals exist for Linux?
• 8.8 How many people use Linux?
• 8.9 How should I pronounce Linux?

9. Frequently encountered error messages.

• 9.1 Modprobe can't locate module, ``XXX,'' and similar messages.
• 9.2 Unknown terminal type linux and similar.
• 9.3 lp1 on fire
• 9.4 INET: Warning: old style ioctl... called!
• 9.5 ld: unrecognized option '-m486'
• 9.6 GCC says Internal compiler error.
• 9.7 make says Error 139
• 9.8 shell-init: permission denied when I log in.
• 9.9 No utmp entry. You must exec ... when I log in.
• 9.10 Warning--bdflush not running.
• 9.11 Warning: obsolete routing request made.
• 9.12 EXT2-fs: warning: mounting unchecked file system.
• 9.13 EXT2-fs warning: maximal count reached.
• 9.14 EXT2-fs warning: checktime reached.
• 9.15 df says Cannot read table of mounted file systems.
• 9.16 fdisk says Partition X has different physical/logical ...
• 9.17 fdisk: Partition 1 does not start on cylinder boundary.
• 9.18 fdisk says partition n has an odd number of sectors.
• 9.19 mtools says cannot initialize drive XYZ
• 9.20 At the start of booting: Memory tight
• 9.21 My syslog says `end_request: I/O error, ...'.
• 9.22 You don't exist. Go away.

10. The X Window System.

• 10.1 Does Linux support X Windows?
• 10.2 Where can I get an XF86Config for my system?
• 10.3 xterm logins show up strangely in who, finger.
• 10.4 I can't get X Windows to work right.

11. Questions applicable to very out-of-date software.

• 11.1 fdisk says cannot use nnn sectors of this partition.
• 11.2 GCC sometimes uses huge amounts of virtual memory and thrashes.

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. Administrative information and acknowledgments.

• 13.1 Feedback is invited.
• 13.2 Formats in which this FAQ is available.
• 13.3 Authorship and acknowledgments.
• 13.4 Disclaimer and Copyright.