If you are experiencing problems with GRUB, you may need to disable the
graphical boot screen. To do this, become the root user and edit the
/boot/grub/grub.conf file.
Within the grub.conf file, comment out the line
which begins with splashimage by inserting
the # character at the beginning of the
line.
Press [Enter] to exit the editing mode.
Once the boot loader screen has returned, type b to
boot the system.
Once you reboot, the grub.conf file is
reread and any changes you have made take effect.
You may re-enable the graphical boot screen by uncommenting (or
adding) the above line back into the grub.conf
file.
If you have installed the X Window System but are not seeing a
graphical desktop environment once you log into your Red Hat Enterprise Linux system, you
can start the X Window System graphical interface using the command
startx.
Once you enter this command and press [Enter], the
graphical desktop environment is displayed.
Note, however, that this is just a one-time fix and does not change
the log in process for future log ins.
To set up your system so that you can log in at a graphical login
screen, you must edit one file, /etc/inittab, by
changing just one number in the runlevel section. When you are finished,
reboot the computer. The next time you log in, you are presented with a
graphical login prompt.
Open a shell prompt. If you are in your user account, become root by
typing the su command.
Now, type gedit /etc/inittab to edit the file with
gedit. The file
/etc/inittab opens. Within the first screen,
a section of the file which looks like the following appears:
# Default runlevel. The runlevels used by RHS are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
#
id:3:initdefault: |
To change from a console to a graphical login, you should change the
number in the line id:3:initdefault: from a
3 to a 5.
 | Warning |
|---|
| | Change only the number of the default runlevel
from 3 to 5.
|
Your changed line should look like the following:
When you are satisfied with your change, save and exit the file using
the [Ctrl]-[Q] keys. A
window appears and asks if you would like to save the changes. Click
Save.
The next time you log in after rebooting your system, you are
presented with a graphical login prompt.
If you are having trouble getting X (the X Window System) to
start, you may not have installed it during your installation.
If you want X, you can either install the packages from the Red Hat Enterprise Linux
CD-ROMs or perform an upgrade.
If you elect to upgrade, select the X Window System packages, and
choose GNOME, KDE, or both, during the upgrade package selection process.
If you are having trouble with the X server crashing when anyone other
than root logs in, you may have a full file system (or, a lack of
available hard drive space).
To verify that this is the problem you are experiencing, run the
following command:
The df command should help you diagnose which
partition is full. For additional information about df
and an explanation of the options available (such as the
-h option used in this example), refer to the
df man page by typing man df at a
shell prompt.
A key indicator is 100% full or a percentage above 90% or 95% on a
partition. The /home/ and /tmp/
partitions can sometimes fill up quickly with user files. You can make
some room on that partition by removing old files. After you free up some
disk space, try running X as the user that was unsuccessful before.
If you did not create a user account in the
Setup Agent, log in as root and use the
password you assigned to root.
If you cannot remember your root password, boot your system as
linux single.
Itanium users must enter boot commands with elilo
followed by the boot command.
If you are using an x86-based system and GRUB is your
installed boot loader, type e for edit when the GRUB
boot screen has loaded. You are presented with a list of items in the
configuration file for the boot label you have selected.
Choose the line that starts with kernel and type
e to edit this boot entry.
At the end of the kernel line, add:
Press [Enter] to exit edit mode.
Once the boot loader screen has returned, type b to
boot the system.
Once you have booted into single user mode and have access to the
# prompt, you must type passwd root,
which allows you to enter a new password for root. At this point you can
type shutdown -r now to reboot the system with the new
root password.
If you cannot remember your user account password, you must become
root. To become root, type su - and enter your root
password when prompted. Then, type passwd
<username>. This allows you to enter a new password
for the specified user account.
If the graphical login screen does not appear, check your hardware for
compatibility issues. The Hardware Compatibility
List can be found at:
Sometimes, the kernel does not recognize all of your memory
(RAM). You can check this with the cat /proc/meminfo
command.
Verify that the displayed quantity is the same as the known amount of
RAM in your system. If they are not equal, add the following line to the
/boot/grub/grub.conf:
Replace xx with the amount of RAM you
have in megabytes.
In /boot/grub/grub.conf, the above example
would look similar to the following:
#NOTICE: You have a /boot partition. This means that
# all kernel paths are relative to /boot/
default=0
timeout=30
splashimage=(hd0,0)/grub/splash.xpm.gz
title Red Hat Enterprise Linux (2.6.9-1.641_EL)
root (hd0,0)
kernel /vmlinuz-2.6.9-1.641_EL ro root=/dev/hda3 mem=128M |
Once you reboot, the changes made to
grub.conf are reflected on your system.
Once you have loaded the GRUB boot screen, type e for
edit. You are presented with a list of items in the configuration file for
the boot label you have selected.
Choose the line that starts with kernel
and type e to edit this boot entry.
At the end of the kernel line,
add
where xx equals the amount of RAM in your
system.
Press [Enter] to exit edit mode.
Once the boot loader screen has returned, type b to
boot the system.
Itanium users must enter boot commands with elilo
followed by the boot command.
Remember to replace xx with the amount of RAM
in your system. Press [Enter] to boot.
If you are not sure how to set up your printer or are having trouble
getting it to work properly, try using the
Printer Configuration Tool.
Type the system-config-printer command at a shell
prompt to launch the Printer Configuration Tool. If you
are not root, it prompts you for the root password to continue.
If, for some reason, you do not hear sound and know that you do have a
sound card installed, you can run the Sound Card Configuration Tool
(system-config-soundcard) utility.
To use the Sound Card Configuration Tool, choose
=>
=> . A small text box
pops up prompting you for your root password.
You can also type the system-config-soundcard command
at a shell prompt to launch the Sound Card Configuration Tool. If
you are not root, it prompts you for the root password to continue.
To run the text-based configuration tool, as root, type
sndconfig in a terminal window. Note, the
sndconfig application is not installed by default but can
be found on the Red Hat Enterprise Linux CD-ROMs.
If the Sound Card Configuration Tool does not work (if the
sample does not play and you still do not have audio sounds), there are
alternatives, although they are not quite as simple as running the
Sound Card Configuration Tool. You can edit your
modules.conf file (this strategy is not recommended for
most new users), or refer to the documentation that came with your sound
card for more information.
If you are having trouble with the Apache-based
httpd service or Sendmail hanging at startup, make sure
the following line is in the /etc/hosts file:
127.0.0.1 localhost.localdomain localhost |
If you have an NVIDIA chipset and have just updated your kernel, you may
experience problems with the video card, such as not having any video
output.
If you experience a similar problem, you should download the latest
kernel drivers available for your NVIDIA chipset. For more information,
refer to:
