LINUX Q & A

Question:
What are the minimum hardware and space requirements for installing Red Hat Linux on my PC?
Answer:
This depends on the version of Red Hat Linux you wish to install. Different releases contain various sets of application packages and different versions of the Linux kernel, both of which are important when judging system requirements.
Red Hat Linux 7.1:
  • Processor — Any x86 processor (minimum required); Intel Pentium or AMD-K6 (minimum recommended).
  • RAM — 32 MB RAM (minimum required); 64 MB RAM (minimum recommended).
  • Hard Drive Free Space — 650 MB (minimum required); 1.5 GB (minimum required for Workstation-class installation with GNOME and KDE; 1.2 GB with only one); 1.2 GB (minimum required for Server-class installation); 1.5 GB (minimum required for Laptop-class installation with GNOME and KDE; 1.2 GB with only one); 2.4 GB (minimum required for Custom-class installation if every package is selected); 1.2 GB (minimum required to use automatic partitioning); 3 GB (minimum recommended to allow space for updates and additional software).
Red Hat Linux 7.0:
  • Processor — Any x86 processor (minimum required); Intel Pentium or AMD-K6 (minimum recommended).
  • RAM — 32 MB RAM (minimum required); 64 MB RAM (minimum recommended).
  • Hard Drive Free Space — 500 MB (minimum required); 1.5 GB (minimum required for Workstation-class installation with GNOME and KDE; 1.2 GB with only one); 1.2 GB (minimum required for Server-class installation); 1.5 GB (minimum required for Laptop-class installation with GNOME and KDE; 1.2 GB with only one); 2.4 GB (minimum required for Custom-class installation if every package is selected); 900 GB (minimum required to use automatic partitioning); 2.5 GB (minimum recommended to allow space for updates and additional software).
Red Hat Linux 6.2:
  • Processor — Any x86 processor (minimum required); Intel Pentium or AMD-K6 (minimum recommended).
  • RAM — 16 MB RAM (minimum required); 32 MB RAM (minimum recommended).
  • Hard Drive Free Space — 500 MB (minimum required); 1.2 GB (minimum required for Workstation-class installation with GNOME and KDE; 700 MB with only one); 1.7 GB (minimum required for Server-class installation); 1.7 GB (minimum required for Custom-class installation if every package is selected); 2 GB (minimum recommended to allow space for updates and additional software).
___________________________________________________________

Programming Tools and Compilers Included

Question:
What programming tools/compilers does Red Hat Linux include with its distribution?
Answer:
C, C++, FORTRAN, Pascal, assembly, BASIC, Perl, Python, Tcl/Tk, LISP, Scheme, as well as a functional debugger and memory debugging library.
___________________________________________________________

Multimedia Tools Included

Question:
What multimedia tools are shipped with the boxed set of Red Hat Linux 7.1?
Answer:
Image viewers for JPEG, GIF, PNG, TIFF, MPEG, AVI, and Quicktime video viewers.
___________________________________________________________

Graphical Programs Included

Question:
What type of graphical program is shipped with Red Hat Linux 7.1?
Answer:
GIMP 1.2.1, an image manipulation, retouching, and paint program. See http://www.gimp.org for more information.
___________________________________________________________

Publishing Tools Included

Question:
What types of publishing tools are shipped with Red Hat Linux 7.1?
Answer:
TeX, LaTex, groff text formatting systems, PostScript, PDF, and DVI previewers.
___________________________________________________________

Mail Servers Included

Question:
What mail servers are shipped with Red Hat Linux?
Answer:
Sendmail, POP, and IMAP servers are included with Red Hat Linux.
___________________________________________________________

Red Hat Linux as a File Server

Question:
Can I use Red Hat Linux as a file server?
Answer:
Yes, Samba and NFS are included to facilitate the use of Red Hat Linux as a file server. Windows clients can access files and print using a Red Hat Linux server in the same way as they can using a native Windows NT/2000 file/print server.
___________________________________________________________

The Graphical Environment for Red Hat Linux

Question:
Does Red Hat Linux include an X Window System?
Answer:
Yes, XFree86 version 4.0.3 is included, which supports many advanced 3D, high-end video cards. In addition, XFree86 version 3.3.6 is also included and provides excellent support for older and less powerful video cards.
Both XFree86 versions give you the graphical environment to act as a platform for a variety of window managers and desktop environments, all of which are entirely configurable to meet your specific needs.
___________________________________________________________

Running Windows Programs in Red Hat Linux

Question:
Will my Microsoft applications be able to run on Red Hat Linux?
Answer:
No, only applications compiled for compatibility with the Linux kernel will run on the Red Hat Linux operating system. However, it is possible to run WINE, an implementation of Windows 3.x and Win32 APIs, to run many DOS and Windows applications. WINE is included with Red Hat Linux PowerTools, and more information about it can be found at http://www.winehq.com.
You can also run VMware, which provides you with a virtual machine that will run Linux and another operating system concurrently. For more information, see http://www.vmware.com.
___________________________________________________________

Obtaining Red Hat Linux

Question:
How can I get Red Hat Linux?
Answer:
Red Hat Linux is available on CD-ROM directly from Red Hat, Inc., at http://www.redhat.com/commerce or through various Red Hat Linux resellers. It is also available via the Red Hat FTP server (ftp://ftp.redhat.com/pub/redhat/linux/) and many mirror sites (http://www.redhat.com/download/mirror.html).
You are also able to purchase official Red Hat Linux boxed products from stores such as Wal-Mart, CompUSA, and many other retail establishments.
Due to the open source licenses that Red Hat Inc uses for its products, the source code is also available for download in SRPM packages. RPM source packages allow for you to install the source code for a particular application on your computer and build binary RPM files from the source. Red Hat Linux is licensed using the GNU General Public License. More information about the GPL can be found at http://www.gnu.org/copyleft/gpl.html.
___________________________________________________________

Installing Multiple Operating Systems

Question:
I have a blank hard drive and would like to install DOS or Windows 95/98/ME and Red Hat Linux onto it. What is the best method of doing this?
Answer:
It is recommended to install the other operating system first, before installing Red Hat Linux. This allows DOS or Windows 95/98/ME to configure itself to work correctly with your system's hardware and possibly write values to the Master Boot Record (MBR) to allow it to boot properly. If Red Hat Linux were installed first, the other operating system may elect to overwrite existing entries in the MBR, leaving you unable to boot into Red Hat Linux. By installing the other OS first, Red Hat Linux will allow you to boot into either operating system when your computer starts up.
You will probably need to do the entire process of installing DOS or Windows 95/98/ME using several different steps. First, start the installation, but if the operating system partitions the entire drive for itself, see if you can exit the installation program and use the native fdisk to create a primary partition of the size you want to have available for that particular OS. Then, reboot and go through the installation process again. Normally, DOS or Windows 95/98/ME will only use the space that you just set aside for it. Once the installation is finished, you can then begin to install Red Hat Linux.
If you need to install to install Red Hat Linux and Windows NT/2000 on the same machine, please see the section called Installing Linux and Windows NT on the Same Machine.
___________________________________________________________

Creating an Installation Boot Disk

Question:
How do I create an installation boot disk?
Answer:
Two different methods for producing an installation boot disk exist, depending if you want to create the disk using UNIX/Linux or DOS/Windows.
Using UNIX/Linux, mount the first Red Hat Linux installation CD-ROM, enter the /images directory, insert a floppy in your drive, and use the dd command to copy the image to the floppy: 
dd if=boot.img of=/dev/fd0 bs=1440k
Using DOS or Windows, use the rawrite command in the /dosutils directory on the CD-ROM. Documentation on using rawrite in this way is available in /dosutils/rawrite3.doc.
To make floppies under DOS, Win95, or NT, first boot into DOS and change to the CD-ROM directory (for example, D:).
Enter the dosutils directory and run rawrite. 
cd \dosutils
rawrite.exe
When prompted for a disk for the boot image, enter \path\to\boot.img.
Then run rawrite again and, when prompted, enter \path\to\supp.img.
The .img files are boot images and can be found in the images directory on the first Red Hat Linux installation CD-ROM.
___________________________________________________________

Difference Between Linux and DOS Disk Names

Question:
I have an IDE system, and I am confused by how Linux sets up drives in comparison to DOS. Can you explain this?
Answer:
Linux sets up the drive system in a very different way than DOS, and this can be quite confusing for a new Linux user. Instead of calling the first hard drive C:, it will be usually referred to as a combination of letters signifying what kind of bus (sd for SCSI, hd for IDE) and in which sequence the drive falls on that bus. Finally, a number is placed onto the end to specify the particular partition on the drive that is being referenced.
For IDE hard drives, the layout depends on which IDE channel the drive is located and whether it is the master or slave drive on that channel. 
Channel         Jumper          hdx
===================================
ide0            master          hda
ide0            slave           hdb
ide1            master          hdc
ide1            slave           hdd
ide2            master          hde
ide2            slave           hdf
ide3            master          hdg
ide3            slave           hdh


ide0 = primary
ide1 = secondary
ide2 = tertiary
ide3 = quarternary
The partition number follows an old PC/X86 standard that there is a limit of 4 primary partitions per hard drive, but one of those partitions can be designated as an extended partition. Inside of this extended partition, logical partitions can be specified (for most drives you can have up to 12 logical drives in the extended partition, for a total of 16 partitions).
The numbering scheme is broken into the following:
  • 1-4 primary partitions
  • 5-16 logical partitions
___________________________________________________________

Installation Problems with IDE CD-ROM

Question:
Red Hat Linux is having trouble detecting my IDE CD-ROM drive during the install. Can I force the installation program to see it?
Answer:
Sometimes IDE CD-ROM drives will not be detected either due to the fact that they are on a IDE channel your system's BIOS doesn't know about or that, when queried, the IDE channel replies back with data that the Red Hat Linux installation program thinks is bogus. (For example, early NEC IDE CD-ROMs respond with data saying that it is an IDE floppy drive instead of a CD-ROM.)
To solve your problem, you need to specify the the CD-ROM drive from the LILO boot prompt.
When you see boot: or LILO: prompt, you should type linux hdX=cdrom, where X is the IDE letter that Linux would specify for that drive depending on which IDE bus it is located.
___________________________________________________________

Installing Red Hat Linux from a Hard Drive

Question:
I do not have a CD-ROM that will work with Linux, and I can not install from the network. Is there another method?
Answer:
If you cannot perform a CD-ROM or network installation for whatever reason, you can elect to install using your hard drive.
Starting with Red Hat Linux 7.1, you must use the ISO disk images of the installation CD-ROMs; you can no longer pull off each of the various installation directories and properly arrange them on your hard drive. Simply clear enough space on your hard drive to hold both of the ISO images and download them, placing both of them in the same directory. Next, create a boot floppy, boot from it, and elect to perform a hard drive installation, pointing the installation program to the directory holding the ISO images. Then, proceed normally with the installation.
For installations of Red Hat Linux versions prior to 7.1, the following steps are required:
First, have a DOS partition that is formatted in FAT16, and create a directory called RedHat. From there, you should copy the items from the first Red Hat Linux installation CD-ROM over to the hard drive. 
mkdir C:\RedHat
   mkdir C:\RedHat\base
   mkdir C:\RedHat\RPMS
   copy E:\RedHat\base C:\RedHat\base
   copy E:\RedHat\RPMS C:\RedHat\RPMS
If you do not have enough disk space for copying the entire RPMS directory tree over to your hard drive, you will need to look in the \RedHat\base\comps file for the RPMs that are needed in the base and any other installation sections you would like to install.
Once you have done this, you can start the install using a boot floppy and choose the hard drive installation method. You will be asked to insert the supplemental floppy and a progress meter will pop up to show you what is happening. Once the supplemental disk has been loaded, you will be presented with the next screen on the install.
___________________________________________________________

Laptop Installation Problems

Question:
I am having trouble getting Linux installed or configured on my laptop computer. What should I do?
Answer:
Laptops are one of the hardest pieces of hardware to support for any operating system. Many times, the company that constructs the hardware has to tweak a chipset to make it fit in the confined structure or meet certain power requirements. These changes are usually only documented internally for trade secret reasons and can only be reverse-engineered or worked around.
When Red Hat Support finds itself with a laptop question, our first (and sometimes only) reference is the Linux Laptop Pages, which can be found at http://www.linux-laptop.net.
___________________________________________________________

Signal 11 or Signal 7 Problems During Installation

Question:
During the install, I get a fatal signal 11 or signal 7. What does this mean, and what can I do?
Answer:
Signal 11's and signal 7's are errors indicating a hardware error in memory or on the bus. This can be due to problems in executables or with the hardware of the system. The Linux kernel tends to make much greater use of capabilities of a system's CPU, cache, and memory. Therefore, it is more prone to faulting on marginal or defective hardware.
The first thing to do is check to see if you have the latest installation and supplemental floppies from Red Hat. Check the errata page (http://www.redhat.com/support/errata) for updates and also the FTP site (ftp://ftp.redhat.com) to see if newer versions are available. If the latest images still fail, it may be due to problems with your hardware. Common suspects are memory (RAM) or the CPU-cache. Try turning off the CPU-cache in the BIOS and see if the problem goes away. Also try swapping the RAM modules around in the motherboard slots to see if it is either slot or memory related.
The premier site on the net for this problem can be found at http://www.bitwizard.nl/sigll/.
___________________________________________________________

Upgrade Problem: can't find a valid RPM database Error

Question:
I am trying to upgrade my Red Hat system to the current release, but it complains that it can't find a valid RPM database. What do I need to do?
Answer:
The problem is that a very few earlier versions of RPM would write the database in a way that seems corrupted to later versions. Rebuilding the database fixes the install problems. You will need to upgrade the RPM application on your system to the one on the installation CD-ROM, and rebuild the databases.
The first thing to do is mount the first Red Hat Linux installation CD-ROM on the system. 
mount /mnt/cdrom
After doing this, upgrade the RPM application using the latest version on the CD-ROM: 
cd /mnt/cdrom/RedHat/RPMS
rpm -Uvh --nodeps --force rpm-*rpm
When the new RPM application is installed, rebuild the RPM database. 
rpm --rebuilddb
This will put the RPM database in a format that the RPM application used by the Red Hat Linux installation program can use (since they are the same).
___________________________________________________________

Booting Linux from the Installation Boot Disk

Question:
I have Red Hat Linux installed on an IDE drive, and for whatever reason, I need to boot from floppy. How can I boot my system from the installation boot disk?
Answer:
If you have installed Linux onto an IDE hard drive, you can boot from the installation floppy using the following method.
Insert the installation floppy and restart the machine. At the boot: prompt, type the following: 
vmlinuz root=/dev/hdXY
  [Example: vmlinuz root=/dev/hdb5 ]
Where X is the IDE drive letter and Y is the partition on the drive where you installed the root (/) partition for Red Hat Linux.
For more information about the naming conventions for IDE or SCSI hard drives and their partitions, refer to the section called Difference Between Linux and DOS Disk Names.
___________________________________________________________

Where to Go for Updates

Question:
Where can I find updates for packages shipped with Red Hat Linux?
Answer:
Red Hat, Inc. posts all official updates at http://www.redhat.com/support/errata. You can also go to ftp://updates.redhat.com.
Also check the contrib directory on our FTP mirrors for packages that users have contributed. We also make periodic announcements to the redhat-announce-list with updates.
___________________________________________________________

Contents of the Source CD-ROM

Question:
During the install, I was not asked to use one of the Red Hat Linux installation CD-ROMs. When I use the X program glint on it, it reports that there are no RPMs, but when I look at the directories, I see lots of them. What is going on?
Answer:
This CD-ROM in the Red Hat Linux boxed set (known as CD 4 in version 7.0 and higher or CD 2 in version 6.2 and below) contains the source code RPMs (SRPM) for all of the open source applications that are on the other CD-ROMs. From these source RPMs, you can build all the open source applications in the Red Hat Linux distribution.
The reason that glint does not see source RPMs is due to the fact that SRPMS are not stored in any of the RPM databases. This makes it almost impossible to tell if you have installed an source RPM (package-name.src.rpm) before or are overwriting an older version. Thus, you will need to use the plain rpm command to install these items.
rpm -ivh package-name.src.rpm will install the source code into the directory that the maintainer of that SRPM used. The data in the source RPMs packaged by Red Hat are installed into /usr/src/redhat by default.
Rebuilding and improving on RPMs is beyond the scope of this answer. The book Maximum RPM and the RPM man pages are good sources of information on this subject. An online version of Maximum RPM can be found at http://www.redhat.com/support/books/max-rpm/max-rpm-html, and the book is also available for sale at the Red Hat Store (http://www.redhat.com/apps/commerce).
___________________________________________________________

Installing RPM Packages

Question:
How do I install an RPM package?
Answer:
For most RPM packages, you can simply type rpm -Uvh filename.
This will upgrade the RPM, if you already have it on your system, or install it, if it is not already installed.
One notable occasion when you would not want to use the -U flag is when you are installing a kernel RPM. In this case, you will want to leave your old kernel in place, at least temporarily, in case the new kernel does not boot. This can be accomplished by using the -i flag in the place of the -U flag in the rpm command, such as rpm -ivh kernel-package-name.
For more information about installing new kernels, please see http://www.redhat.com/support/resources/howto/kernel-upgrade/kernel-upgrade.html.
___________________________________________________________

More About RPM

Question:
How do I use RPM? What are some general commands that I will use with this application? Also, for whatever reason, I think files have changed on my system but I don't know which ones. Can RPM help?
Answer:
In general, normal usage of the rpm command can be summarized as follows:
  • Installation/Upgrading/Removal
    • To install a package: rpm -ivh filename 
      rpm -ivh somepackage.1.1-4.i386.rpm
    • To upgrade a package: rpm -Uvh filename 
      rpm -Uvh somepackage.1.1-5.i386.rpm
    • To remove a package: rpm -e packagename 
      rpm -e somepackage
    • Also, for upgrading or installing some packages, you may need to use additional flags to force the install to happen. It is only recommended to use these if you know why these flags were needed. 
      --force    will overwrite files that are owned by other packages.

      --nodeps   will install even if the package needs packages that were not installed.
  • Querying
    • To see if a package is installed: rpm -q packagename 
      rpm -q somepackage
    • To get info on an installed package: rpm -qi packagename 
      rpm -qi somepackage
    • To list which files belong to a package: rpm -ql packagename 
      rpm -ql somepackage
    • To see what package a file belongs to: rpm -qf path-to-filename 
      rpm -qf /usr/bin/some_executable
One can usually join various query commands together, so rpm -qil will give info and list all the files in the package.
To look at an RPM filename that isn't installed, you add the p to the query line. 
rpm -qilp somepackage.1.1-4.i386.rpm
This will list the information and the files contained in somepackage.

More Advanced

More advanced usages can be found in the man page for RPM and at the website, http://www.rpm.org.

Verification

To see what files on the system may have changed from their initial settings, you can use RPM to check up on them.
The command rpm -Va will give you a list of all files that have changed in one form or another since the package associated with it was installed. This can be a lot of files (and a lot may be changed due to post installation work). To just see what packages have changed so that you can verify them more individually, you can do the following: 
rpm -Va --pipe "awk '{print $2}' | xargs rpm -qf | sort -u" &> /tmp/file1
Then look in the file /tmp/file1 to see all of the packages that have been changed after their installation.
___________________________________________________________

Getting Started

Question:
I have installed Red Hat Linux version 6.2 or earlier onto my machine. I am presented with a prompt that says: 
LILO:
What do I do now? Can you give me instructions on the next steps?
Answer:
Red Hat Linux 7.0 and greater use a graphical boot screen, so you will not see any prompt. If you would like to see a LILO: prompt with these versions, press [Ctrl]-[X].
After you have completed an installation of Red Hat Linux version 6.2 or earlier, the machine should reboot and you will be presented with a prompt that looks like: 
LILO:
If you press the [Enter] key, it will begin the booting process of the Linux system. After a short time (from 20 seconds to 10 minutes depending on the machine speed and services running), you will see a clear screen with the text similar to: 
Red Hat Linux release 6.2 (Zoot)
kernel 2.2.14-5.0 on an i686
        
login: _
At the login: prompt, you will need to log in as the root user. Type root and press [Enter] again. You should be prompted for a password: 
login: root
password: _
Type in the password you set during the install and press [Enter]. For security reasons, the password is not echoed onto the screen. If all goes well the machine should log you in. If you are prompted for a password again, the text you typed did not match the install password. Try again, being careful to use correct capitalization. This is the standard text-mode or runlevel 3 login screen. You may be expecting a graphical login but have ended up at the text-mode virtual terminal screen.
Now you should create a new user account and password, one that will be used for day-to-day work with the system. Next, exit and log back in as that user.
Once you are logged in, you can use the command startx to start a GUI environment.
If you are new at using Linux, there are several websites that we recommend, including:
The following good books will also help you get started:
  • LINUX in a Nutshell by Ellen Siever, Jessica P. Hekman, Stephen Figgins, and Stephen Spainhour; O'Reilly & Associates
  • Running Linux by Matt Welsh and Lar Kaufman; O'Reilly & Associates
  • Red Hat Linux for Dummies by Jon "maddog" Hall; IDG
___________________________________________________________

Installing Linux and Windows NT on the Same Machine

Question:
How do I install Windows NT and Linux onto the same machine?
Answer:
If you need to install Windows NT and Linux on the same machine, read the Linux and NT HOWTO that has been prepared by Bernd Reichert. The latest version can be found at http://www.tldp.org/HOWTO/mini/Linux+NT-Loader.html.
Since this guide is extremely helpful, only a brief summary is presented below:
  • Partition and install Windows NT first, making sure to leave space for Linux to place its partitions. If possible, do not create any logical partitions, as we have had reports of this causing problems. Get NT running and its boot loader happy. If you haven't already, make an NT rescue boot floppy just in case something goes wrong later in this process.
  • Install Linux and install LILO to the root (/) partition instead of the Master Boot Record (MBR).
  • If you are using Red Hat Linux 5.1 or later, use the rescue boot floppy you created during the install to boot Linux initially.
  • Edit the /etc/lilo.conf file to remove the prompt line and any other operating systems listed. The prompt action can occasionally confuse the NT boot loader. Here is an example /etc/lilo.conf file that has been set up for NT. 
    boot=/dev/hda
    map=/boot/map
    install=/boot/boot.b
    timeout=50
    image=/boot/vmlinux-2.2.12-20
    label=Linux
    root=/dev/hda5 #(make sure that you put your correct root partition here)
    read-only
  • Follow the rest of the directions in the mini HOWTO on making the NT OS loader Linux-aware.
A more recent mini HOWTO that discusses more installation can be found at http://www.tldp.org/HOWTO/mini/Linux+WinNT.html.
___________________________________________________________

Adding Users

Question:
How do I add users?
Answer:
First, log in as root and run the adduser command. 
adduser username
Make certain that you also set up a password for the new user. 
passwd username
___________________________________________________________

Mount Failed Error

Question:
I'm trying to install and I keep getting mount failed. What should I do?
Answer:
If you are performing a full installation, make certain that you have set up the partitions as ext2 or Linux Native, depending on which partitioning tool you used. Also, make sure that you have created and initiated your swap partition.
There are five virtual consoles available during installation. Two of these consoles, Install Log (accessed by [Ctrl]-[Alt]-[F3]) and System Log (accessed by [Crtl]-[Alt]-[F4]) may prove to be beneficial in pinpointing the install problem you have encountered.
If you are running an upgrade, switch to a virtual terminal and make certain that none of the partitions are already mounted. Also, check /etc/fstab for filesystem types that aren't listed in /proc/filesystems.
___________________________________________________________

Forgetting the Root Password

Question:
I forgot my root password. What do I do?
Answer:
When the system comes to the LILO: prompt, type linux single.
When you get the # prompt you will need to type passwd root.
This will update the password to a newer one. At this point you can type shutdown -r now and the system should boot up normally. You can now use your new root password to gain root access.
___________________________________________________________

Avoiding Running the fsck Command After Each Reboot

Question:
Every time I turn my computer off, when I turn it back on, it makes me run fsck command on my partitions. Why?
Answer:
The most likely cause for this is that your partitions are not being unmounted properly when you last shutdown the machine. Linux is very much like NT and other operating systems in that it needs to be properly shutdown before being powered off or there could be disk or file corruptions and other inconsistencies.
The most important thing you can do is make sure that you are shutting down the machine properly. This can be done through one of two methods:
  • If you are in text mode (runlevel 3), you should log in as root and type shutdown -r now.
  • If you are using the GUI mode (runlevel 5), there should be a system button on the GDM login screen. (This is the screen that asks for your username and password.) Click on System and then pull down to Halt.
Either of these methods will cleanly halt your machine and you should see a line that says Power Down when it is safe to turn off the machine. If you are running APM, Linux will try to stop the machine via the BIOS.
___________________________________________________________

Getting Sound to Work With Linux

Question:
How do I get sound to work with Linux?
Answer:
Most of the time, you only need to login as root and run the sndconfig command. More information can be found at http://www.redhat.com/support/manuals/RHL-7.1-Manual/getting-started-guide/ch-fun.html#S1-FUN.
In a few rare cases or when using an older version of Red Hat Linux, setting up sound can be a challenge, primarily because most people have plug and play sound cards. This section of the FAQ tries to attack this issue from several different angles to try to cover all bases.
First, you will need to either disable plug and play on the card (via jumpers or card setup tools). You can also change your boot method to use loadlin.exe from Windows (as Windows would then have set up the plug and play hardware).
The command to set up sound is called sndconfig. You will need to log in as root (and if you are using the X Window System, open a terminal). At the prompt type sndconfig. This will walk you through setting up your sound card.
If you have problems with sndconfig, here are a couple of other ways to attack the problem.
The sndconfig program tries to set up a good set of default values for the plug and play settings and then load the appropriate modules. If it cannot find a good set of values itself, you can also try: 
/usr/sbin/sndconfig --noautoconfig
This command will let you manually specify the plug and play values for the card. You need to choose these wisely however. The values from Windows will probably work if it's the only plug and play device in the machine, but check out: 
cat /proc/interrupts
cat /proc/ioports
cat /proc/dma
cat /proc/pci
to find a set of resources that will work.
Enter them in and continue. It should then load the proper modules and play the sound.
You can also try letting sndconfig configure itself as close as it can get to the real values of your card. Then, you can edit /etc/modules.conf (or /etc/conf.modules in early version of Red Hat Linux) to use the correct values. Your /etc/modules.conf may have a couple of lines that look something like: 
alias sound sb
options sb irq=7 io=0x320 dma=3,5
To reload the modules type: 
/etc/rc.d/init.d/sound stop
/etc/rc.d/init.d/sound start
This should load up the sb module with the proper resources.
You can also try this: 
cd /etc
pico modules.conf (or conf.modules)
delete any lines about sb or opl3
save the file
reboot
Then run /usr/sbin/sndconfig again.
Finally, you can try using the isapnptools programs.
Type this: 
/sbin/pnpdump > /etc/isapnp.conf
The pnpdump command probes to see what plug and play devices are installed and generates a template file called /etc/isapnp.conf for isapnp to read.
Once you have chosen a good set of resources for the card, make sure they don't conflict with any other cards. To see other resources, check the following: 
cat /proc/pci
cat /proc/interrupts
cat /proc/ioports
cat /proc/dma
Then type 
/sbin/isapnp /etc/isapnp.conf
to set up the devices. If this does not work, you can edit this file with a text editor (vi, pico, emacs, etc.) and adjust the values to fit those of your card. The file format is a little obtuse, so you may want to check http://www.roestock.demon.co.uk/isapnptools for more information.
If it's not a plug and play sound card, and you know the values for the resources it uses, you can just set them manually by editing /etc/modules.conf (or /etc/conf.modules for older versions of Red Hat Linux). 
----example---------
alias sound sb
alias midi opl3
options opl3 io=0x388
options sb io=0x220 irq=7 dma=0,1 mpu_io=0x300
----example---------
You can also type man isapnp.conf for a more detailed description of the format.
Then run: 
/etc/rc.d/init.d/sound stop
/etc/rc.d/init.d/sound start
You may need to go though this a few times to get good values. This is what sndconfig is supposed to do automatically, but it doesn't always work for all cards.
If all this fails, report problems to the sound-list@redhat.com so that they can be worked on.
___________________________________________________________

Screen Blanking

Question:
Every time I leave my computer for a few minutes, the screen goes blank. How can I fix this?
Answer:
If you have a screen saver running, you may want to turn it off. In text mode, the kernel will "screen-save" your system unless you use: 
setterm -powersave off -blank 0
Otherwise, if you hear disk drives speed up or other sounds, this is probably APM kicking in. Disable APM from starting at boot time by logging in as root and typing ntsysv. Then deselect APM. Leave ntsysv and you will need to reboot the machine. (This is one of the few services that you have to restart the system, as APM is so deeply connected to the kernel that a full reset is needed.)
___________________________________________________________

bash: command not found

Question:
I compiled a program called hello but when I try to run it, the command line responds with bash: hello command not found. Why won't my programs run on Red Hat?
Answer:
This problem is generally caused by the location of the program not being specified in your general path. The path is where Linux (like Windows) will search for a working executable. The current working directory is not in your path because of possible security exploits of a command masking itself as another one.
To run your file, you can either put the directory with hello in your path (you can find out what the path is by typing echo $PATH) OR move the hello program into a directory that is in your path. Alternatively, and perhaps most common, you can simply run hello by typing ./hello from within the directory containing the program.
___________________________________________________________

Getting Online With a Modem

Question:
I can't get my modem to work. Can you help?
Answer:
First, check to see if your modem is a supported device. Double-check the Hardware Compatibility List at http://hardware.redhat.com.
Verify that your modem is being detected by the system and that it is not conflicting with other resources. You can check this with the following commands (as seen in this example): 
cat /proc/ioports

0000-001f : dma1
0020-003f : pic1
0040-005f : timer
0060-006f : keyboard
0070-007f : rtc
0080-008f : dma page reg
00a0-00bf : pic2
00c0-00df : dma2
00f0-00ff : fpu
0170-0177 : ide1
01f0-01f7 : ide0
0220-022f : soundblaster
02f8-02ff : serial(auto)
0330-0333 : MPU-401 UART
0376-0376 : ide1
0388-038b : Yamaha OPL3
03c0-03df : vga+
03f6-03f6 : ide0
03f8-03ff : serial(auto)
d000-d07f : eth0
d800-d807 : ide0
d808-d80f : ide1
      
cat /proc/interrupts

          CPU0       
 0:    1296380          XT-PIC  timer
 1:      30736          XT-PIC  keyboard
 2:          0          XT-PIC  cascade
 5:          1          XT-PIC  soundblaster
 8:          1          XT-PIC  rtc
10:      73593          XT-PIC  eth0
12:     159669          XT-PIC  PS/2 Mouse
13:          1          XT-PIC  fpu
14:     246863          XT-PIC  ide0
15:     584998          XT-PIC  ide1
NMI:         0
Examples of conflicting resources would be your modem and some other port sharing an interrupt. In the PC world, COM 1 (/dev/ttyS0) and COM 3 (/dev/ttyS3) will try to share the same interrupt unless told otherwise. While this works in some systems, we have generally found that it leads to a degradation of service.
Next, we recommend that you use minicom to double-check that you are getting a signal back from your modem. Once you have determined this, refer to the following sites for information on setting up a PPP connection using rp3 and wvdial:
Questions like this are also excellent questions for the Red Hat users' mailing list. There are many experienced Red Hat users on the list who might be of assistance on a matter of this sort. To subscribe to redhat-list, go to https://listman.redhat.com/mailman/listinfo/redhat-list.
There is also a compiled listing of past posts to this group. You may find the answer to your question here:
___________________________________________________________

Preventing Netscape From Crashing

Question:
Netscape keeps crashing when I reach a page with Java applets in it. I have also noticed that some of my applications do not display fonts correctly. What is going on?
Answer:
If could be possible that your system does not have a complete list of fontpath for X to use.
To see if this is the problem you are facing, use the command: 
chkfontpath --list
You should get output that looks like the following: 
Current directories in font path:
1: /usr/X11R6/lib/X11/fonts/misc:unscaled
2: /usr/X11R6/lib/X11/fonts/75dpi:unscaled
3: /usr/X11R6/lib/X11/fonts/100dpi:unscaled
4: /usr/X11R6/lib/X11/fonts/misc
5: /usr/X11R6/lib/X11/fonts/Type1
6: /usr/X11R6/lib/X11/fonts/Speedo
You should then add the 75dpi scaled font to your path list using the command: 
chkfontpath --add /usr/X11R6/lib/X11/fonts/75dpi
This should fix the problem you are seeing.
However, if problems persist. refer to http://home.netscape.com/eng/mozilla/4.6/relnotes/unix-4.6.html#unix (or Help - Release notes in the menu).
Basically, if Netscape exhibits consistent problems on pages containing Javascript, check your ~/.mailcap file, and remove this line if it is in that file: 
application/x-javascript;;\ 
    
x-mozilla-flags=save
___________________________________________________________

Problems Trying to Connect with Netscape

Question:
I can dial up to my ISP just fine, but I can't use Netscape. It says cannot connect to remote host. What is wrong?
Answer:
What you are seeing occurs from one of two possible problems.
The first problem could be that your DNS (Domain Name Server) information may not being set correctly during dial-up.
Red Hat Linux 6.2 uses wvdial which can determine this for most ISPs, but may have problems with some.
For Red Hat Linux 6.0 and earlier you will need to specify your ISP's DNS servers in your /etc/resolv.conf. Contact your ISP for this information and edit the file to include those settings.
Here's an example: 
search example.com example.com
nameserver 198.79.53.11
nameserver 198.79.53.10
Another possible reason for this problem may be that you are expecting action like what might be seen in a Windows environment. When Windows detects that you are looking for something on a network and you have a modem in your system, it will try to start that modem connection. Linux requires you to start the connection manually (most easily done through the Main Menu => Programs => Internet => RH PPP Dialer in the GNOME menu, or by using the much older the X Window System program usernet).
___________________________________________________________

Boot Hangs During sendmail, httpd, or smb

Question:
I have installed Linux, and it seems to initially start booting. However, it gets down to something called sendmail, httpd, or smb and then the machine seems to hang. What is happening and what should I do?
Answer:
If, after the install, the system seems to hang when it reaches certain processes like Sendmail, Apache, or Samba, there is probably a network problem. The most common cause is that Linux can not look up the name of the machine you have called the box (if you set up networking to have a machine name). The machine is currently paused waiting for the network timeout of DNS lookups and will eventually bring up the login prompt. Login in as root and check the usual culprits for a problem.

If you are directly on a network with a DNS server, make sure the file /etc/resolv.conf has the correct values for your machine's DNS server. Check with your system administrator to make sure that the values are correct.
If you are using Linux on a network without a DNS server (or this box is going to be the DNS server), then you will need to edit the /etc/hosts file to have the hostname and IP address so that the lookups will occur correctly. The format of the /etc/hosts file is:
Labels: , , , , , , ,