Some Computer Hints


Read Hat Linux

Below are given some system management commands. Most are graphical. On old versions of Red Hat Linux replace the system prefix with redhat.

setup General Setup (TUI)
hwbrowser Hardware Browser
system-config-authentication Authentication Configuration
authconfig Authentication Configuration (TUI)
system-config-boot Boot Loader Configuration
system-config-date
system-config-time
Time and Date Properties
system-config-display Display Settings
system-config-httpd HTTP Configuration
system-config-keyboard Keyboard Configuration
system-config-language Language Configuration
system-config-lvm Logical Volume Management
system-config-mouse Mouse Configuration
system-config-network Network Configuration
system-config-network-cmd Network Configuration (command-line)
system-config-network-druid Network Hardware Configuration
system-control-network Network Device Control
system-config-nfs NFS Server Configuration
system-config-packages Package Management
system-config-printer Printer Configuration
system-config-printer-tui Printer Configuration (TUI)
system-config-rootpassword Root Password Entry
system-config-samba Samba Server Configuration
system-config-securitylevel Security Level ("firewall") Configuration
system-config-securitylevel-tui Security Level ("firewall") Configuration (TUI)
system-config-services Services (xinetd & init.d) Configuration
system-config-soundcard Audio Devices Configuration
system-config-users User Manager
system-logviewer Log Viewer
gnome-system-monitor GNOME System Monitor
mkbootdisk Create a boot disk (command-line)

To display Red Hat release use:

# cat /etc/redhat-release

To make updates from web run:

# up2date

To list installed packages enter

# rpm -qa

For filesystem check use the command:

# e2fsck -cttv /dev/hdxy

To instal GRUB on first disk enter:

# /sbin/grub-install --recheck /dev/hda

To disable Ctrl+Alt+Del combination on the console edit the /etc/inittab file, change the lines:

# Trap CTRL-ALT-DELETE
ca::ctrlaltdel:/sbin/shutdown -t3 -r now

to

# Disable CTRL-ALT-DELETE
ca::ctrlaltdel:/bin/echo "<ctrl><alt><del> disabled"

and enter the command

# kill -HUP 1

or

# init q

To check whether daemons are enabled or not (at specific runlevels) execute

# chkconfig --list

For example:

# chkconfig --list | grep -e http -e smb -e mysql

To enable a service at a specific level, (for example http) run:

# chkconfig --level 5 httpd on

The /etc/sysconfig/ directory contains service parameter files.


To mount a Windows share (using Samba) enter the command:

# mount -t smbfs -o username=domain\\user //computer/share /localdirectory

To allow root access for rlogin, rsh, and rexec add the following lines to /etc/securetty:

rexec
rsh
rlogin

To configure sendmail edit /etc/mail/sendmail.mc and execute

# make -C /etc/mail

Also edit /etc/aliases and run

# newaliases

To make your system an NTP client, add the following lines to /etc/ntp.conf:

server tick.usno.navy.mil
restrict 192.5.41.40 mask 255.255.255.255 nomodify notrap noquery

Additional NTP servers may be added.

To make your system an NTP server, add the following lines to /etc/ntp.conf:

restrict 10.0.0.0 mask 255.0.0.0 notrust nomodify notrap nopeer

assuming your network has the following addresses: 10.*.*.*. You can restart ntpd using the command

# service ntpd restart

To view the status of your NTP server connections run:

# ntpq -c peers

To enable XDMCP on your system, set Enable=true under section [xdmcp] in file /etc/X11/gdm/gdm.conf and then run

# gdm-restart