Operation Manual

• The machinecannot reach the authenticationserveror directoryserverthat
contains that user'sinformation.
• There may be problemswith the X Window Systemauthenticatingthis particular
user, especiallyif the user'shome has been used with another Linux distribution
prior to installingthe current one.
To locate the cause of the login failures with networkauthentication, proceed as
follows:
1 Checkwhetherthe userremembered theirpassword correctlybefore you
start debugging the whole authentication mechanism.
2 Determine the directoryserverwhichthe machinerelieson for authentication
and make sure that it is up and running and properly communicatingwith the
other machines.
3 Determine that the user'susernameand password workon othermachines
to make sure that his authenticationdata exists and is properly distributed.
4 See if anotherusercan log in to the misbehavingmachine.If anotheruser
can log in withoutdifficulty or if
root
can log in, log in and examinethe
/var/
log/messages
file. Locatethe time stampsthat correspondto the login attempts
and determine if PAM has producedany error messages.
5 Try to log in from a console(using[
Ctrl
] +[
Alt
] +[
F1
]). If this is successful,
the problem is not with PAM or the directory serveron which the user'shome
is hosted, becauseit is possible to authenticatethis user on this machine. Try
to locate any problems with the X Window Systemor the desktop(GNOME or
KDE). For more information, refer to Section“Login Successful but GNOME
DesktopFails” (page 98) and Section “Login Successfulbut KDE DesktopFails”
(page 99).
6 If the user'shome directoryhas beenusedwith anotherLinux distribution,
remove the
Xauthority
file in the user'shome.Use a consolelogin via[ Ctrl]
+[
Alt
] +[
F1
] and run
rm .Xauthority
as this user. This should eliminateX
authenticationproblems for this user. Try graphical login again.
7 If graphicallogin still fails,do a consolelogin with[
Ctrl
] +[
Alt
] +[
F1
]. Try to
start an X sessionon another display—thefirst one(
:0
) is alreadyin use:
startx -- :1
This should bring up a graphicalscreen and your desktop.If it does not, check
the log files of the X Window System(
/var/log/Xorg. displaynumber.log
)or
the log file for your desktopapplications(
.xsession-errors
in the user'shome
directory) for any irregularities.
8 If the desktopcould not startbecauseof corrupt configurationfiles,proceed
with Section “Login Successfulbut GNOME DesktopFails” (page 98) or Section
“Login Successfulbut KDE Desktop Fails” (page 99).
Help and Troubleshooting 97