The /etc/sysconfig/ directory contains a variety of system
configuration files for Red Hat Enterprise Linux.
This chapter outlines some of the files found in the
/etc/sysconfig/ directory, their function, and their
contents. The information in this chapter is not intended to be complete,
as many of these files have a variety of options that are only used in
very specific or rare circumstances.
The following files are normally found in the
/etc/sysconfig/ directory:
amd
apmd
arpwatch
authconfig
autofs
clock
desktop
devlabel
dhcpd
exim
firstboot
gpm
harddisks
hwconf
i18n
init
ip6tables-config
iptables-config
irda
keyboard
kudzu
mouse
named
netdump
network
ntpd
pcmcia
radvd
rawdevices
samba
sendmail
selinux
spamassassin
squid
system-config-securitylevel
system-config-users
system-logviewer
tux
vncservers
xinetd
Note
If some of the files listed here are not present in the
/etc/sysconfig/ directory, the corresponding
program may not be installed.
The following sections offer descriptions of these files. Files not
listed here as well as extra file options found in the
/usr/share/doc/initscripts-<version-number>/sysconfig.txt
file (replace <version-number> with the
version of the initscripts package). Alternatively,
looking through the initscripts in the /etc/rc.d/
directory can prove helpful.
The /etc/sysconfig/apmd file is used by
apmd to configure what power settings to
start/stop/change on suspend or resume. This file configures how
apmd functions at boot time, depending on whether the
hardware supports Advanced Power Management
(APM) or whether the user has configured the
system to use it. The apm daemon is a monitoring
program that works with power management code within the Linux
kernel. It is capable of alerting users to low battery power on laptops
and other power-related settings.
The /etc/sysconfig/arpwatch file is used to pass
arguments to the arpwatch daemon at boot time. The
arpwatch daemon maintains a table of Ethernet MAC
addresses and their IP address pairings. By default, this file sets
the owner of the arpwatch process to the user
pcap as well as sends any messages to
the root mail queue. For more information regarding
available parameters for this file, refer to the
arpwatch man page.
The /etc/sysconfig/autofs file defines custom
options for the automatic mounting of devices. This file controls the
operation of the automount daemons, which automatically mount file
systems when you use them and unmount them after a period of
inactivity. File systems can include network file systems, CD-ROMs,
diskettes, and other media.
The /etc/sysconfig/autofs file may contain the
following:
LOCALOPTIONS="<value>",
where "<value>" is a string for
defining machine specific automount rules. The default value
is an empty string ("").
DAEMONOPTIONS="<value>",
where "<value>" is the timeout
length in seconds before unmounting the device. The default value
is 60 seconds ("--timeout=60").
UNDERSCORETODOT=<value>,
where <value> is a binary value
that controls whether to convert underscores in file names into
dots. For example, auto_home to
auto.home and auto_mnt to
auto.mnt. The default value is 1 (true).
DISABLE_DIRECT=<value>,
where <value> is a binary value
that controls whether to disable direct mount support, as the
Linux implementation does not conform to the Sun Microsystems'
automounter behavior. The default value is 1 (true), and allows
for compatibility with the Sun automounter options specification
syntax.
The /etc/sysconfig/devlabel is the
devlabel configuration file. It should not be
modified by hand, but rather, configured using the
/sbin/devlabel command.
For instructions on using the devlabel
command, refer to the chapter titled User-Defined Device
Names in the Red Hat Enterprise Linux System Administration Guide.
The /etc/sysconfig/dhcpd file is used to pass
arguments to the dhcpd daemon at boot time. The
dhcpd daemon implements the Dynamic Host
Configuration Protocol (DHCP) and the Internet Bootstrap Protocol
(BOOTP). DHCP and BOOTP assign hostnames to machines on the network.
For more information about what parameters are available in this file,
refer to the dhcpd man page.
The /etc/sysconfig/exim file allows messages to
be sent to one or more clients, routing the messages over whatever
networks are necessary. The file sets the default values for exim to
run. Its default values are set to run as a background daemon and to
check its queue each hour in case something has backed up.
The values include:
DAEMON=<value>,
where <value> is one of the
following:
yes — exim should be
configured to listen to port 25 for incoming
mail. yes implies the use of Exim's
-bd options.
no — exim should not be
configured to listen to port 25 for incoming mail.
QUEUE=1h which is given to
exim as
-q$QUEUE. The -q option is
not given to exim if
/etc/sysconfig/exim exists and
QUEUE is empty or undefined.
The first time the system boots, the /sbin/init
program calls the etc/rc.d/init.d/firstboot
script, which in turn launches the
Setup Agent. This application allows
the user to install the latest updates as well as additional
applications and documentation.
The /etc/sysconfig/firstboot file tells the
Setup Agent application not to run on
subsequent reboots. To run it the next time the system boots,
remove /etc/sysconfig/firstboot and execute
chkconfig --level 5 firstboot on.
The /etc/sysconfig/gpm file is used to pass
arguments to the gpm daemon at boot time. The
gpm daemon is the mouse server which allows mouse
acceleration and middle-click pasting. For more information about what
parameters are available for this file, refer to the
gpm man page. By default, the
DEVICE directive is set to
/dev/input/mice.
The /etc/sysconfig/harddisks file tunes the
hard drive(s). An administrator can also use
/etc/sysconfig/hardiskhd[a-h] to configure
parameters for specific drives.
Warning
Do not make changes to this file without careful consideration. By
changing the default values, it is possible to corrupt all of the
data on the hard drive(s).
The /etc/sysconfig/harddisks file may contain the following:
USE_DMA=1, where setting this value to 1
enables DMA. However, with some chipsets and hard drive
combinations, DMA can cause data corruption. Check the
hard drive documentation or with the manufacturer before enabling
this option. By default, this entry is commented out,
and therefore disabled.
Multiple_IO=16, where a setting of 16
allows for multiple sectors per I/O interrupt. When enabled, this
feature reduces operating system overhead by 30-50%. Use
with caution. By default, this entry is commented out,
and therefore disabled.
EIDE_32BIT=3 enables (E)IDE 32-bit I/O
support to an interface card. By default, this entry is commented
out, and therefore disabled.
LOOKAHEAD=1 enables drive
read-lookahead. By default, this entry is commented out, and
therefore disabled.
EXTRA_PARAMS= specifies where extra
parameters can be added. By default, there are no parameters listed.
The /etc/sysconfig/hwconf file lists all the
hardware that kudzu detected on the system, as
well as the drivers used, vendor ID, and device ID information. The
kudzu program detects and configures new and/or
changed hardware on a system. The
/etc/sysconfig/hwconf file is not meant to be
manually edited. If edited, devices could suddenly show up as being
added or removed.
The /etc/sysconfig/init file controls how the
system appears and functions during the boot process.
The following values may be used:
BOOTUP=<value>,
where <value>
is one of the following:
color — The standard color
boot display, where the success or failure of devices
and services starting up is shown in different colors.
verbose — An old style
display which provides more information than purely a
message of success or failure.
Anything else means a new display, but without
ANSI-formatting.
RES_COL=<value>,
where <value>
is the number of the column of the screen to start status
labels. The default is set to 60.
MOVE_TO_COL=<value>,
where <value>
moves the cursor to the value in the RES_COL
line via the echo -en command.
SETCOLOR_SUCCESS=<value>,
where <value>
sets the success color via the echo -en
command. The default color is set to green.
SETCOLOR_FAILURE=<value>,
where <value>
sets the failure color via the echo -en
command. The default color is set to red.
SETCOLOR_WARNING=<value>,
where
<value> sets
the warning color via the echo -en
command. The default color is set to yellow.
SETCOLOR_NORMAL=<value>,
where
<value>
resets the color to "normal" via the echo
-en.
LOGLEVEL=<value>,
where <value>
sets the initial console logging level for the kernel. The
default is 3; 8 means everything (including debugging), while 1
means only kernel panics. The syslogd daemon
overrides this setting once started.
PROMPT=<value>,
where
<value> is
one of the following boolean values:
The /etc/sysconfig/ip6tables-config file stores
information used by the kernel to set up IPv6 packet filtering
at boot time or whenever the ip6tables service
is started.
Do not modify this file by hand unless familiar with how to construct
ip6tables rules. Rules also can be created manually
using the /sbin/ip6tables command. Once created,
add the rules to the /etc/sysconfig/ip6tables
file by typing the following command:
/sbin/service ip6tables save
Once this file exists, any firewall rules saved in it persists
through a system reboot or a service restart.
The /etc/sysconfig/iptables-config file stores
information used by the kernel to set up packet filtering services
at boot time or whenever the service is started.
Do not modify this file by hand unless you are familiar with
constructing iptables rules. The easiest way to
add rules is to use the Security Level Configuration Tool
(system-config-securitylevel) application to
create a firewall. These applications automatically edit this file
at the end of the process.
Rules can also be created manually using the
/sbin/iptables command. Once created, add the
rule(s) to the /etc/sysconfig/iptables file by
typing the following command:
/sbin/service iptables save
Once this file exists, any firewall rules saved in it persists
through a system reboot or a service restart.
The /etc/sysconfig/irda file controls how
infrared devices on the system are configured at startup.
The following values may be used:
IRDA=<value>,
where <value>
is one of the following boolean values:
yes —
irattach runs and periodically
checks to see if anything is trying to connect to the
infrared port, such as another notebook computer trying to
make a network connection. For infrared devices to work on
the system, this line must be set to yes.
no —
irattach does not run, preventing
infrared device communication.
DEVICE=<value>,
where <value>
is the device (usually a serial port) that handles infrared
connections. A sample serial device entry could be
/dev/ttyS2.
DONGLE=<value>,
where <value>
specifies the type of dongle being used for infrared
communication. This setting exists for people who use serial
dongles rather than real infrared ports. A dongle is a device that
is attached to a traditional serial port to communicate via
infrared. This line is commented out by default because notebooks
with real infrared ports are far more common than computers with
add-on dongles. A sample dongle entry could be
actisys+.
DISCOVERY=<value>,
where <value>
is one of the following boolean values:
yes — Starts
irattach in discovery mode, meaning it
actively checks for other infrared devices. This must be
turned on for the machine to actively look for an infrared
connection (meaning the peer that does not initiate the
connection).
The /etc/sysconfig/keyboard file controls
the behavior of the keyboard. The following values may be used:
KEYBOARDTYPE="sun|pc" where
sun means a Sun keyboard is attached on
/dev/kbd, or pc means a
PS/2 keyboard connected to a PS/2 port.
KEYTABLE="<file>",
where <file>
is the name of a keytable file.
For example: KEYTABLE="us". The files
that can be used as keytables start in
/lib/kbd/keymaps/i386 and branch into
different keyboard layouts from there, all labeled
<file>.kmap.gz.
The first file found beneath
/lib/kbd/keymaps/i386 that matches the
KEYTABLE setting is used.
The /etc/sysconfig/kuzdu file triggers a safe
probe of the system hardware by kudzu at boot
time. A safe probe is one that disables serial port probing.
SAFE=<value>,
where <value> is one of the
following:
The /etc/sysconfig/mouse file is used to
specify information about the available mouse. The following
values may be used:
FULLNAME="<value>",
where "<value>"
refers to the full name of the kind of mouse being used.
MOUSETYPE="<value>",
where "<value>"
is one of the following:
imps2 — A generic USB wheel mouse.
microsoft — A
Microsoft™ mouse.
mouseman — A
MouseMan™ mouse.
mousesystems — A Mouse
Systems™ mouse.
ps/2 — A PS/2 mouse.
msbm — A
Microsoft™ bus mouse.
logibm — A
Logitech™ bus mouse.
atibm — An
ATI™ bus mouse.
logitech — A
Logitech™ mouse.
mmseries — An older
MouseMan™ mouse.
mmhittab — An mmhittab mouse.
XEMU3="<value>",
where "<value>"
is one of the following boolean values:
yes — The mouse only has two
buttons, but three mouse buttons should be emulated.
no — The mouse already has three
buttons.
XMOUSETYPE="<value>",
where "<value>"
refers to the kind of mouse used when X is running. The options
here are the same as the MOUSETYPE setting in
this same file.
DEVICE=<value>,
where <value> is the mouse
device.
A sample value, /dev/input/mice, is a
symbolic link that points to the actual mouse device.
The /etc/sysconfig/named file is used to pass
arguments to the named daemon at boot time. The
named daemon is a Domain Name
System (DNS) server which
implements the Berkeley Internet Name Domain
(BIND) version 9 distribution. This server
maintains a table of which hostnames are associated with IP
addresses on the network.
Currently, only the following values may be used:
ROOTDIR="</some/where>",
where
</some/where>
refers to the full directory path of a configured chroot
environment under which named runs. This chroot
environment must first be configured. Type info
chroot for more information.
OPTIONS="<value>",
where <value>
is any option listed in the man page for named
except -t. In place of -t, use
the ROOTDIR line above.
For more information about available parameters for this
file, refer to the named man page. For detailed
information on how to configure a BIND DNS server, refer to Chapter 12 Berkeley Internet Name Domain (BIND). By default, the file contains no parameters.
The /etc/sysconfig/netdump file is the
configuration file for the /etc/init.d/netdump
service. The netdump service sends both oops data
and memory dumps over the network. In general,
netdump is not a required service; only run it if
absolutely necessary. For more information about what parameters
are available for this file, refer to the netdump man page.
The /etc/sysconfig/network file is used to
specify information about the desired network configuration. The
following values may be used:
NETWORKING=<value>,
where <value>
is one of the following boolean values:
yes — Networking should be
configured.
no — Networking should not be
configured.
HOSTNAME=<value>,
where <value>
should be the Fully Qualified Domain Name
(FQDN), such as
hostname.expample.com, but can be whatever
hostname is necessary.
Note
For compatibility with older software that some users may need
to install, such as trn, the
/etc/HOSTNAME file should contain the same
value as set here.
GATEWAY=<value>,
where <value>
is the IP address of the network's gateway.
GATEWAYDEV=<value>,
where <value>
is the gateway device, such as eth0.
NISDOMAIN=<value>,
where <value>
is the NIS domain name.
The /etc/sysconfig/ntpd file is used to pass
arguments to the ntpd daemon at boot time. The
ntpd daemon sets and maintains the system clock to
synchronize with an Internet standard time server. It implements
version 4 of the Network Time Protocol (NTP). For more information
about what parameters are available for this file, use a Web browser
to view the following file:
/usr/share/doc/ntp-<version>/ntpd.htm
(where <version> is the version
number of ntpd). By default, this file sets the
owner of the ntpd process to the user
ntp.
The /etc/sysconfig/pcmcia file is used to specify
PCMCIA configuration information. The following values may be used:
PCMCIA=<value>,
where <value>
is one of the following:
yes — PCMCIA support should be
enabled.
no — PCMCIA support should not be
enabled.
PCIC=<value>,
where <value>
is one of the following:
i82365 — The computer has an
i82365-style PCMCIA socket chipset.
tcic — The computer has a
tcic-style PCMCIA socket chipset.
PCIC_OPTS=<value>,
where <value>
is the socket driver (i82365 or
tcic) timing parameters.
CORE_OPTS=<value>,
where <value> is the list of
pcmcia_core options.
CARDMGR_OPTS=<value>,
where <value>
is the list of options for the PCMCIA cardmgr
(such as -q for quiet mode,
-m to look for loadable kernel modules in the
specified directory, and so on). Read the
cardmgr man page for more information.
The /etc/sysconfig/radvd file is used to pass
arguments to the radvd daemon at boot time. The
radvd daemon listens for router requests and sends
router advertisements for the IP version 6 protocol. This service
allows hosts on a network to dynamically change their default routers
based on these router advertisements. For more information about
available parameters for this file, refer to the
radvd man page. By default, this file sets the
owner of the radvd process to the user
radvd.
The /etc/sysconfig/samba file is used to pass
arguments to the smbd and the
nmbd daemons at boot time. The
smbd daemon offers file sharing connectivity for
Windows clients on the network. The nmbd daemon
offers NetBIOS over IP naming services. For more information about
what parameters are available for this file, refer to the
smbd man page. By default, this file sets
smbd and nmbd to run in daemon
mode.
The /etc/sysconfig/selinux file contains the
basic configuration options for SELinux. This file is a symbolic link to
/etc/selinux/config. For more information on SELinux,
refer to Chapter 21 SELinux.
The /etc/sysconfig/sendmail file allows messages
to be sent to one or more clients, routing the messages over whatever
networks are necessary. The file sets the default values for the
Sendmail application to run. Its default values are set to run as a
background daemon and to check its queue each hour in case something
has backed up.
Values include:
DAEMON=<value>,
where <value> is one of the
following:
yes — Sendmail should be
configured to listen to port 25 for incoming
mail. yes implies the use of Sendmail's
-bd options.
no — Sendmail should not be
configured to listen to port 25 for incoming mail.
QUEUE=1h which is given to Sendmail as
-q$QUEUE. The -q option is
not given to Sendmail if
/etc/sysconfig/sendmail exists and
QUEUE is empty or undefined.
The /etc/sysconfig/spamassassin file is used to
pass arguments to the spamd daemon (a daemonized
version of Spamassassin) at boot time. Spamassassin is an email spam
filter application. For a list of available options, refer to the
spamd man page. By default, it configures
spamd to run in daemon mode, create user
preferences, and auto-create whitelists (allowed bulk senders).
The /etc/sysconfig/squid file is used to pass
arguments to the squid daemon at boot time. The
squid daemon is a proxy caching server for Web
client applications. For more information on configuring a
squid proxy server, use a Web browser to open the
/usr/share/doc/squid-<version>/
directory (replace <version> with the
squid version number installed on the system). By
default, this file sets squid to start in daemon
mode and sets the amount of time before it shuts itself down.
The /etc/sysconfig/system-config-securitylevel
file contains all options chosen by the user the last time the
Security Level Configuration Tool
(system-config-securitylevel) was run. Users should
not modify this file by hand. For more information about the
Security Level Configuration Tool, refer to the chapter
titled Basic Firewall Configuration in the
Red Hat Enterprise Linux System Administration Guide.
The /etc/sysconfig/system-config-users file is
the configuration file for the graphical application,
User Manager. This file is used to filter
out system users such as root,
daemon, or lp. This file is
edited by the Preferences => Filter
system users and groups pull-down menu in the
User Manager application and should never
be edited by hand. For more information on using this application,
refer to the chapter called User and Group
Configuration in the Red Hat Enterprise Linux System Administration Guide.
The /etc/sysconfig/system-logviewer file is the
configuration file for the graphical, interactive log viewing
application, Log Viewer. This file is
edited by the Edit =>
Preferences pull-down menu in the
Log Viewer application and should not be
edited by hand. For more information on using this application, refer
to the chapter called Log Files in the
Red Hat Enterprise Linux System Administration Guide.
The /etc/sysconfig/tux file is the configuration
file for the Red Hat Content Accelerator (formerly known as TUX), the
kernel-based Web server. For more information on configuring the Red
Hat Content Accelerator, use a Web browser to open the
/usr/share/doc/tux-<version>/tux/index.html
file (replace <version> with the
version number of TUX installed on the system). The parameters
available for this file are listed in
/usr/share/doc/tux-<version>/tux/parameters.html.
The /etc/sysconfig/vncservers file configures the
way the Virtual Network Computing
(VNC) server starts up.
VNC is a remote display system which allows users to view the desktop
environment not only on the machine where it is running but across
different networks on a variety of architectures.
It may contain the following:
VNCSERVERS=<value>,
where <value>
is set to something like "1:fred", to indicate
that a VNC server should be started for user fred on display
:1. User fred must have set a VNC password using the
vncpasswd command before attempting to connect
to the remote VNC server.
Note that when using a VNC server, communication with it is
unencrypted and it should not be used on an untrusted network. For
specific instructions concerning the use of SSH to secure VNC
communication, read the information found online at https://www.uk.research.att.com/archive/vnc/sshvnc.html.
To find out more about SSH, refer to Chapter 20 SSH Protocol in the
Red Hat Enterprise Linux System Administration Guide.
The /etc/sysconfig/xinetd file is used to pass
arguments to the xinetd daemon at boot time. The
xinetd daemon starts programs that provide Internet
services when a request to the port for that service is received. For
more information about available parameters for this file, refer to
the xinetd man page. For more information on the
xinetd service, refer to Section 17.3 xinetd.
