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Chapter 4. The sysconfig Directory
The /etc/sysconfig/ directory is where a variety of system configuration files for Red Hat Linux are stored.
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.
4.1. Files in the /etc/sysconfig/ Directory
The following files are normally found in the /etc/sysconfig/ directory:
amd
apmd
arpwatch
authconfig
cipe
clock
desktop
dhcpd
firstboot
gpm
harddisks
hwconf
i18n
identd
init
ipchains
iptables
irda
keyboard
kudzu
mouse
named
netdump
network
ntpd
pcmcia
radvd
rawdevices
redhat-config-securitylevel
redhat-config-users
redhat-logviewer
samba
sendmail
soundcard
spamassassin
squid
tux
ups
vncservers
xinetd
 | Note |
|---|---|
If some of the files listed are not present in the /etc/sysconfig/ directory, then the corresponding program may not be installed. |
4.1.1. /etc/sysconfig/amd
The /etc/sysconfig/amd file contains various parameters used by amd, which allow for the automatic mounting and unmounting of file systems.
4.1.2. /etc/sysconfig/apmd
The /etc/sysconfig/apmd file is used by apmd as a configuration for what power settings to start/stop/change on suspend or resume. It is configured to turn on or off apmd at boot time, depending on whether the hardware supports Advanced Power Management (APM) or whether or not 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 capable of alerting users to low battery power on laptops and other power-related settings.
4.1.3. /etc/sysconfig/arpwatch
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. For more information about what parameters are available for this file, see the arpwatch man page. By default, this file sets the owner of the arpwatch process to the user pcap.
4.1.4. /etc/sysconfig/authconfig
The /etc/sysconfig/authconfig file sets the kind of authorization to be used on the host. It contains one or more of the following lines:
USEMD5=<value>, where <value> is one of the following:
yes — MD5 is used for authentication.
no — MD5 is not used for authentication.
USEKERBEROS=<value>, where <value> is one of the following:
yes — Kerberos is used for authentication.
no — Kerberos is not used for authentication.
USELDAPAUTH=<value>, where <value> is one of the following:
yes — LDAP is used for authentication.
no — LDAP is not used for authentication.
4.1.5. /etc/sysconfig/clock
The /etc/sysconfig/clock file controls the interpretation of values read from the system hardware clock.
The correct values are:
UTC=<value>, where <value> is one of the following boolean values:
true or yes — The hardware clock is set to Universal Time.
false or no — The hardware clock is set to local time.
ARC=<value>, where <value> is the following:
true or yes — The ARC console's 42-year time offset is in effect. This setting is only for ARC- or AlphaBIOS-based Alpha systems. Any other value indicates that the normal UNIX epoch is in use.
SRM=<value>, where <value> is the following:
true or yes — The SRM console's 1900 epoch is in effect. This setting is only for SRM-based Alpha systems. Any other value indicates that the normal UNIX epoch is in use.
ZONE=<filename> — The timezone file under /usr/share/zoneinfo that /etc/localtime is a copy of. The file contains information such as:
ZONE="America/New York"
Earlier releases of Red Hat Linux used the following values (which are deprecated):
CLOCKMODE=<value>, where <value> is one of the following:
GMT — The clock is set to Universal Time (Greenwich Mean Time).
ARC — The ARC console's 42-year time offset is in effect (for Alpha-based systems only).
4.1.6. /etc/sysconfig/desktop
The /etc/sysconfig/desktop file specifies the desktop manager to be run, such as:
DESKTOP="GNOME" |
4.1.7. /etc/sysconfig/dhcpd
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, see the dhcpd man page.
4.1.8. /etc/sysconfig/firstboot
Beginning with Red Hat Linux 8.0, the first time the system boots, the /sbin/init program calls the etc/rc.d/init.d/firstboot script, which in turn launches 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.
4.1.9. /etc/sysconfig/gpm
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, see the gpm man page. By default, it sets the mouse device to /dev/mouse.
4.1.10. /etc/sysconfig/harddisks
The /etc/sysconfig/harddisks file tunes the hard drive(s). The 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 with the hard drive documentation or manufacturer before enabling this option.
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.
EIDE_32BIT=3 enables (E)IDE 32-bit I/O support to an interface card.
LOOKAHEAD=1 enables drive read-lookahead.
EXTRA_PARAMS= specifies where extra parameters can be added.
4.1.11. /etc/sysconfig/hwconf
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.
4.1.12. /etc/sysconfig/i18n
The /etc/sysconfig/i18n file sets the default language, any supported languages, and the default system font. For example:
LANG="en_US.UTF-8" SUPPORTED="en_US.UTF-8:en_US:en" SYSFONT="latarcyrheb-sun16" |
4.1.13. /etc/sysconfig/identd
The /etc/sysconfig/identd file is used to pass arguments to the identd daemon at boot time. The identd daemon returns the username of processes with open TCP/IP connections. Some services on the network, such as FTP and IRC servers, will complain and cause slow responses if identd is not running. But in general, identd is not a required service, so if security is a concern, do not run it. For more information about what parameters are available for this file, see the identd man page. By default, the file contains no parameters.
4.1.14. /etc/sysconfig/init
The /etc/sysconfig/init file controls how the system will appear and function during the boot process.
The following values may be used:
BOOTUP=<value>, where <value> is one of the following:
BOOTUP=color means the standard color boot display, where the success or failure of devices and services starting up is shown in different colors.
BOOTUP=verbose means 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. Defaults 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 color to a color indicating success via the echo -en command. The default color is set to green.
SETCOLOR_FAILURE=<value>, where <value> sets the color to a color indicating failure 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); 1 means nothing except kernel panics. The syslogd daemon overrides this setting once started.
PROMPT=<value>, where <value> is one of the following boolean values:
yes — Enables the key check for interactive mode.
no — Disables the key check for interactive mode.
4.1.15. /etc/sysconfig/ipchains
The /etc/sysconfig/ipchains file contains information used by the ipchains initialization script when setting up the ipchains service.
This file is modified by typing the command /sbin/service ipchains save when valid ipchains rules are in place. Do not manually edit this file. Instead, use the /sbin/ipchains command to configure the necessary packet filtering rules and then save the rules to this file using /sbin/service ipchains save.
Use of ipchains to set up firewall rules is not recommended as it is deprecated and may disappear from future releases of Red Hat Linux. If a firewall is necessary, use iptables instead.
4.1.16. /etc/sysconfig/iptables
Like /etc/sysconfig/ipchains, the /etc/sysconfig/iptables 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 familiar with how to construct iptables rules. The easiest way to add rules is to use Security Level Configuration Tool (redhat-config-securitylevel), the /usr/sbin/lokkit command, or the GNOME Lokkit application to create a firewall. Using these applications automatically edit this file at the end of the process.
Rules can be created manually by using /sbin/iptables: then type /sbin/service iptables save to add the rules to the /etc/sysconfig/iptables file.
Once this file exists, any firewall rules saved in it persists through a system reboot or a service restart.
For more information on iptables see Chapter 16 iptables.
4.1.17. /etc/sysconfig/irda
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 will be run, which 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 will not be run, preventing infrared device communication.
DEVICE=<value>, where <value> is the device (usually a serial port) that handles infrared connections.
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.
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 needs to be turned on for the machine to be actively looking for an infrared connection (meaning the peer that does not initiate the connection).
no — Does not start irattach in discovery mode.
4.1.18. /etc/sysconfig/keyboard
The /etc/sysconfig/keyboard file controls the behavior of the keyboard. The following values may be used:
KEYBOARDTYPE=sun|pc, which is used on SPARCs only. sun means a Sun keyboard is attached on /dev/kbd, and 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.
4.1.19. /etc/sysconfig/kudzu
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:
yes — kuzdu does a safe probe.
no — kuzdu does a normal probe.
4.1.20. /etc/sysconfig/mouse
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 Microsoftâ„¢ mouse.
mouseman — A MouseManâ„¢ mouse.
mousesystems — A Mouse Systemsâ„¢ mouse.
ps/2 — A PS/2 mouse.
msbm — A Microsoftâ„¢ bus mouse.
logibm — A Logitechâ„¢ bus mouse.
atibm — An ATIâ„¢ bus mouse.
logitech — A Logitechâ„¢ mouse.
mmseries — An older MouseManâ„¢ 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.
In addition, /dev/mouse is a symbolic link that points to the actual mouse device.