Linux Frequently Asked Questions with Answers (Part 3 of 6)

rkiesling_at_mainmatter.com
Date: 03/17/05


Date: 17 Mar 2005 05:28:29 GMT

Archive-Name: linux/faq/part3
URL: http://www.mainmatter.com/
Reply-to: rkiesling@mainmatter.com
Posting-Frequency: weekly
Last-modified: 12/04/2001

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]

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]

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.

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.

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.

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.

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/.

4.8. Does Linux Support File System Encryption?

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

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.

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]

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.")

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.

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.

4.14. The System Checks the Ext2fs Partitions Each Reboot.

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

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.")

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.

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.

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/.

5. Porting, Compiling and Obtaining Programs

5.1. How To Compile Programs.

Most Linux software is written in C and compiled with the GNU C
compiler. GCC is a part of every Linux distribution. The latest
compiler version, documentation, and patches are on
ftp://ftp.gnu.org/pub/gnu/.

Programs that are written in C++ must be compiled with the GNU G++
compiler, which is also included in Linux distributions and available
from the same place as GCC.

To build version 2.0.x kernels, you will need GCC version 2.7.2.x,
approximately. Trying to build an early Linux kernel with a different
compiler, like GCC 2.8.x, EGCS, or PGCC, may cause problems because of
GCC related code dependencies. Kernel versions 2.3 and 2.4 should
compile correctly with more recent compilers.

Information on the EGCS compiler is at
http://www.gnu.org/software/gcc/gcc.html.

Note that at this time, the kernel developers are not answering bug
requests for earlier kernels, but instead are concentrating on
developing 2.4.x version kernels and maintaining 2.2.x version
kernels.

[J.H.M. Dassen, Axel Boldt]

5.2. How To Install GNU Software.

On a correctly configured system, installing a GNU software package
requires four steps:

  * With the source.tar.gz archive in the /usr/src/ directory, or
    wherever you maintain your source files, untar and decompress the
    package with the command:
    
tar zxvf package-name.tar.gz

  * Run the ./configure script in the untarred source archive's
    top-level directory with whatever command line arguments you need.
    The options that configure recognizes are usually contained in a
    file called INSTALL or README.
  * Run make. This will build the source code into an executable
    program (or programs) and may take a few minutes or a few hours,
    depending on the speed of the computer and the size of the
    package.
  * Run make install. This will install the compiled binaries,
    configuration files, and any libraries in the appropriate
    directories.

5.3. Where To Get Java.

The Sun Microsystems Java runtime environments and developer's kits
are at http://java.sun.com/java/.

You can also get the source code, which is licensed by Sun
Microsystems.

The home page of IBM's Jikes Java compiler is
http://www10.software.ibm.com/developerworks/opensource/jikes.

There is a version of Sun's HotJava browser for Linux at:
http://www.java.sun.com/products/hotjava/.

Kaffee, a free Java clone, is available from: http://www.kaffe.org/.

There is a resource page of free and commercial Java packages at:
http://www.blackdown.org/java-linux.html.

Netscape Communicator comes with its own version of the Java Runtime
Environment, so if you need Java only to view Web graphics, you may
already have the runtime version of the Java Virtual Machine and
libraries that you need installed on your system. You can download
Communicator from http://www.netscape.com/.

5.4. How To Port XXX to Linux.

In general, *nix programs need very little porting. Simply follow the
installation instructions. If you don't know--and don't know how to
find out--the answers to some of the questions asked during the
installation procedure, you can guess, but this tends to produce buggy
programs. In this case, you're probably better off asking someone else
to do the port. If you have a BSD-ish program, you should try using
-I/usr/include/bsd and -lbsd on the appropriate parts of the
compilation lines.

5.5. What Is ld.so and How To Get It?

ld.so is the dynamic library loader. Each binary using shared
libraries used to have about 3K of start-up code to find and load the
shared libraries. Now that code has been put in a special shared
library, /lib/ld.so, where all binaries can look for it, so that it
wastes less disk space, and can be upgraded more easily. ld.so can be
obtained from http://tsx-11.mit.edu/pub/linux/packages/GCC/ and mirror
sites. The latest version at the time of writing is
ld.so.1.9.5.tar.gz. /lib/ld-linux.so.1 is the same thing for ELF
("What's all this about ELF? ") and comes in the same package as the
a.out loader.

5.6. How To Upgrade the Libraries without Trashing the System.

Warning

Note: You should always have a rescue disk set ready when you perform
this procedure, in the likely event that something goes wrong!

This procedure is especially difficult if you're upgrading very old
libraries like libc4. But you should be able to keep libc4 on the same
system with libc5 libraries for the programs that still need them. The
same holds true for upgrading from libc5 to the newer-yet glibc2
libraries.

The problem with upgrading dynamic libraries is that, the moment you
remove the old libraries, the utilities that you need to upgrade to
the new version of the libraries don't work. There are ways around
around this. One is to temporarily place a spare copy of the run time
libraries, which are in /lib/, in /usr/lib/, or /usr/local/lib/, or
another directory that is listed in the /etc/ld.so.conf file.

For example, when upgrading libc5 libraries, the files in /lib/ might
look something like:

libc.so.5
libc.so.5.4.33
libm.so.5
libm.so.5.0.9

These are the C libraries and the math libraries. Copy them to another
directory that is listed in /etc/ld.so.conf, like /usr/lib/:

$ cp -df /lib/libc.so.5* /usr/lib/
$ cp -df /lib/libm.so.5* /usr/lib/
$ ldconfig

Be sure to run ldconfig to upgrade the library configuration.

The files libc.so.5 and libm.so.5 are symbolic links to the actual
library files. When you upgrade, the new links will not be created if
the old links are still there, unless you use the -f flag with cp. The
-d flag to cp will copy the symbolic link itself, and not the file it
points to.

If you need to overwrite the link to the library directly, use the -f
flag with ln.

For example, to copy new libraries over the old ones, try this. Make a
symbolic link to the new libraries first, then copy both the libraries
and the links to /lib/, with the following commands.

$ ln -sf ./libm.so.5.0.48 libm.so.5
$ ln -sf ./libc.so.5.0.48 libc.so.5
$ cp -df libm.so.5* /lib
$ cp -df libc.so.5* /lib

Again, remember to run ldconfig after you copy the libraries.

If you are satisfied that everything is working correctly, you can
remove the temporary copies of the old libraries from /usr/lib/ or
wherever you copied them.

5.7. How To Use Code or a Compiler Compiled for a 486 on a 386.

Yes, unless it's the kernel.

The -m486 option to GCC, which is used to compile binaries for x486
machines, merely changes certain optimizations. This makes for
slightly larger binaries that run somewhat faster on a 486. They still
work fine on a 386, though, with a small performance hit.

However, from version 1.3.35 the kernel uses 486 or Pentium-specific
instructions if configured for a 486 or Pentium, thus making it
unusable on a 386.

GCC can be configured for a 386 or 486; the only difference is that
configuring it for a 386 makes -m386 the default and configuring for a
486 makes -m486 the default. In either case, these can be overridden
on a per-compilation basis or by editing /usr/lib/gcc-lib/i*-linux/
n.n.n/specs.

There is an alpha version of GCC that knows how to do optimization
well for the 586, but it is quite unreliable, especially at high
optimization settings. The Pentium GCC can be found on
ftp://tsx-11.mit.edu/pub/linux/ALPHA/pentium-gcc/. The ordinary 486
GCC supposedly produces better code for the Pentium using the -m386,
or at least slightly smaller.

5.8. What Does "gcc -O6" Do?

Currently, the same as -O2 (GCC 2.5) or -O3 (GCC 2.6, 2.7). Any number
greater than that does the same thing. The Makefiles of newer kernels
use -O2, and you should probably do the same.

5.9. Where Are linux/*.h and asm/*.h?

The files /usr/include/linux/ and /usr/include/asm/ are often soft
links to the directories where the kernel headers are. They are
usually under /usr/src/kernel*/.

If you don't have the kernel sources, download them. Refer to the
answer: ("How To Upgrade/Recompile a Kernel.")

Then, use rm to remove any garbage, and ln to create the links:

$ rm -rf /usr/include/linux /usr/include/asm
$ ln -sf /usr/src/linux/include/linux /usr/include/linux
$ ln -sf /usr/src/linux/include/asm-<architecture> /usr/include/asm

The assembly language files reside in architecture-specific
directories, so you need to link /usr/src/include/asm to
/usr/src/linux/include/asm-i386 on PC compatible systems, to
/usr/src/linux/include/asm-sparc on Sun Sparc systems, to
/usr/src/linux/include/asm-ppc on PPC systems, and so on.

You'll also find that you may need to do `make config' as in a
newly-unpacked kernel source tree, to create linux/autoconf.h.

5.10. What To Do about Errors Trying to Compile the Kernel.

See the previous question regarding the header files.

Remember that when you apply a patch to the kernel, you must use the
"-p0" or "-p1" option: otherwise, the patch may be misapplied. See the
patch manual page for details.

"ld: unrecognized option `-qmagic'" means that you should get a newer
linker, from ftp://tsx-11.mit.edu/pub/linux/packages/GCC/, in the file
binutils-2.8.1.0.1.bin.tar.gz.

5.11. How To Make a Shared Library.

For ELF,

$ gcc -fPIC -c *.c
$ gcc -shared -Wl,-soname,libfoo.so.1 -o libfoo.so.1.0 *.o

For a.out, get tools-n.nn.tar.gz from
tsx-11.mit.edu/pub/linux/packages/GCC/src/. It comes with
documentation that will tell you what to do. Note that a.out shared
libraries are a very tricky business. Consider upgrading your
libraries to ELF shared libraries. See the ELF HOWTO, at
ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/

5.12. Programs Are Very Large.

With an ELF compiler ("What's All This about ELF? glibc?"), the most
common cause of large executables is the lack of an appropriate .so
library link for one of the libraries you're using. There should be a
link like libc.so for every library like libc.so.5.2.18.

With an a.out compiler the most common cause of large executables is
the -g linker (compiler) flag. This produces (as well as debugging
information in the output file) a program which is statically
linked--one which includes a copy of the C library instead of a
dynamically linked copy.

Other things worth investigating are -O and -O2, which enable
optimization (check the GCC documentation), and -s (or the strip
command) which strip the symbol information from the resulting binary
(making debugging totally impossible).

You may wish to use -N on very small executables (less than 8K with
the -N), but you shouldn't do this unless you understand its
performance implications, and definitely never with daemons.

5.13. Does Linux Support Threads or Lightweight Processes?

As well as the Unix multiprocessing model involving heavyweight
processes, which is of course part of the standard Linux kernel, there
are several implementations of lightweight processes or threads.
Recent kernels implement a thread model, kthreads. In addition, there
are the following packages available for Linux.

  * GNU glibc2 for Linux has optional support for threads. The archive
    is available from the same place as glibc2,
    ftp://ftp.gnu.org/pub/gnu/
  * In sipb.mit.edu:/pub/pthread/ or
    ftp.ibp.fr:/pub/unix/threads/pthreads. Documentation isn't in the
    package, but is available on the World Wide Web at
    http://www.mit.edu:8001/people/proven/home_page.html. Newer Linux
    libc's contain the pthreads source. The GNU Ada compiler on
    ftp://metalab.unc.edu/pub/Linux/devel/lang/ada/gnat-3.01-linux+elf
    .tar.gz contains binaries made from that source code.
  * In ftp://ftp.cs.washington.edu:/pub/qt-001.tar.Z is QuickThreads.
    More information can be found in the technical report, available
    on the same site is /tr/1993/05/UW-CSE-93-05-06.PS.Z.
  * In gummo.doc.ic.ac.uk/rex/ is lwp, a very minimal implementation.
  * In ftp://ftp.cs.fsu.edu:/pub/PART/, an Ada implementation. This is
    useful mainly because it has a lot of Postscript papers that
    you'll find useful in learning more about threads. This is not
    directly usable under Linux.
    
Please contact the authors of the packages in question for details.

5.14. Where To Find lint for Linux.

Roughly equivalent functionality is built into GCC. Use the -Wall
option to turn on most of the useful extra warnings. See the GCC
manual for more details (type F1-i in Emacs and select the entry for
GCC).

There is a freely available program called lclint that does much the
same thing as traditional lint. The announcement and source code are
available at on ftp://larch.lcs.mit.edu/pub/Larch/lclint/; on the
World Wide Web, look at http://lclint.cs.virginia.edu/.

5.15. Where To Find Kermit for Linux.

Kermit is distributed under a non-GPL copyright that makes its terms
of distribution somewhat different. The sources and some binaries are
available on ftp://kermit.columbia.edu.

The WWW Home Page of the Columbia University Kermit project is
http://www.columbia.edu/kermit/.

5.16. How To Use Linux with a Cable Modem.

The www.CablemodemInfo.com and xDSL Web page at
http://www.cablemodeminfo.com/ has a section devoted to Linux.

5.17. Is There an ICQ Program That Runs under Linux?

Several ICQ clients are available on metalab.unc.edu. (Refer to:
"Where Are the Linux FTP Archives?") ICQ itself does not have a Linux
client, but there is a Java client at
http://www.mirabilis.com/download/.

6. Solutions to Common Miscellaneous Problems

6.1. FTP Transfers Seem to Hang.

FTP transfers that die suddenly are due, apparently, to some form of
overrunning buffer. It occurs both with Linux and Microsoft servers.
On Linux systems, The problem seems to occur most commonly with the
distribution's server software.

If you receive ftp: connection refused errors, then the problem is
likely due to a lack of authentication. Refer to "FTP or Telnet Server
Won't Allow Logins.."

One remedy is to be replacing the distribution FTP server with the
Linux port of the OpenBSD FTP server. The home page is:
http://www.eleves.ens.fr:8080/home/madore/programs/

To install the BSD server, follow the installation instructions, and
refer to the manual pages for inetd and inetd.conf. (If you have the
newer xinetd, see below.) Be sure to tell inetd to run the BSD daemon
alone, not as a subprocess of, for example, tcpd. Comment out the line
that begins "ftp" in the /etc/inetd.conf file and replace it with a
line similar to (if you install the new ftpd in /usr/local/sbin/):

# Original entry, commented out.
#ftp stream tcp nowait root /usr/sbin/tcpd /usr/sbin/in.ftpd

# Replacement entry:
ftp stream tcp nowait root /usr/local/sbin/ftpd -l

The replacement daemon will become effective after rebooting or
sending (as root) a SIGHUP to inetd, e.g.:

# kill -HUP inetd

To configure xinetd, create an entry in /etc/xinetd.d per the
instructions in the xinetd.conf manual page. Make sure, again, that
the command-line arguments for ftpd are correct, and that you have
installed the /etc/ftpusers and /etc/pam.d/ftp files. Then restart
xinetd with the command: /etc/rc.d/init.d/xinetd restart. The command
should report "OK," and the restart will be noted in the system
message log.

6.2. Free Dumps Core.

In Linux 1.3.57 and later, the format of /proc/meminfo was changed in
a way that the implementation of free doesn't understand. Get the
latest version, from metalab.unc.edu, in
/pub/Linux/system/Status/ps/procps-0.99.tgz.

6.3. Netscape Crashes Frequently.

Netscape shouldn't crash, if it and the network are properly
configured. Some things to check:

  * Make sure that the MOZILLA_HOME environment variable is correctly
    set. If you installed Netscape under /usr/local/netscape/, for
    example, that should be the value of MOZILLA_HOME. Set it from the
    command line (e.g, "export MOZILLA_HOME="/usr/local/netscape""
    under bash or add it to one your personal or system initialization
    files. Refer to the manual page for your shell for details.
  * If you have a brand-new version of Netscape, try a previous
    version, in case the run-time libraries are slightly incompatible.
    For example, if Netscape version 4.75 is installed (type "netscape
    --version" at the shell prompt), try installing version 4.7. All
    versions are archived at ftp://ftp.netscape.com/.
  * Netscape uses its own Motif and Java Runtime Environment
    libraries. If a separate version of either is installed on your
    system, ensure that they aren't interfering with Netscape's
    libraries; e.g., by un-installing them.
  * Make sure that Netscape can connect to its default name servers.
    The program will appear to freeze and time out after several
    minutes if it can't. This indicates a problem with the system's
    Internet connection; likely, the system can't connect to other
    sites, either.

6.4. FTP or Telnet Server Won't Allow Logins.

This applies to server daemons that respond to clients, but don't
allow logins. On new systems that have Pluggable Authentication
Modules installed, look for a file named, "ftp," or "telnet," in the
directory /etc/pam/ or /etc/pam.d/. If the corresponding
authentication file doesn't exist, the instructions for configuring
FTP and Telnet authentication and other PAM configuration, should be
in /usr/doc/pam-<version>. Refer also to the answer for "FTP server
says: "421 service not available, remote server has closed
connection."."

If it's an FTP server on an older system, make sure that the account
exists in /etc/passwd, especially "anonymous."

This type of problem may also be caused a failure to resolve the host
addresses properly, especially if using Reverse Address Resolution
Protocol (RARP). The simple answer to this is to list all relevant
host names and IP addresses in the /etc/hosts files on each machine. (
Refer to the example /etc/hosts and /etc/resolv.conf files in:
"Sendmail Pauses for Up to a Minute at Each Command..") If the network
has an internal DNS, make sure that each host can resolve network
addresses using it.

If the host machine doesn't respond to FTP or Telnet clients at all,
then the server daemon is not installed correctly, or at all. Refer to
the manual pages: inetd and inetd.conf on older systems, or xinetd and
xinetd.conf, as well as ftpd, and telnetd.

6.5. How To Keep Track of Bookmarks in Netscape?

This probably applies to most other browsers, too. In the
Preferences/Navigator menu, set your home page to Netscape's
bookmarks.html file, which is located in the .netscape (with a leading
period) subdirectory. For example, if your login name is "smith," set
the home page to:

   file://home/smith/.netscape/bookmarks.html

Setting up your personal home page like this will present you with a
nicely formatted (albeit possibly long) page of bookmarks when
Netscape starts. And the file is automatically updated whenever you
add, delete, or visit a bookmarked site.