Sysconfig Information

The following information outlines some of the various files in /etc/sysconfig, their function, and their contents. This information 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.

Files in /etc/sysconfig

The following files are normally found in /etc/sysconfig:

It is possible that your system may be missing a few of them if the corresponding program that would need that file is not installed.

Let's take a look at each one.

/etc/sysconfig/amd

The /etc/sysconfig/amd file contains various parameters used by amd allowing for the automounting and automatic unmounting of filesystems.

/etc/sysconfig/apmd

The /etc/sysconfig/apmd file is used by apmd as a configuration for what things to start/stop/change on suspend or resume. It is set up to turn on or off apmd during startup, depending on whether your hardware supports Advanced Power Management (APM) or if you choose not to use it. apm is a monitoring daemon that works with power management code within the Linux kernel. It can alert you to a low battery if you are using Red Hat Linux on a laptop, among other things.

/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.

/etc/sysconfig/cipe

The /etc/sysconfig/cipe file configures cipe when it starts.

It may contains the following sample values:

  • DEVICE=eth0, which specifies the network adapter that cipe will utilize.

  • PORT=9999, which designates the UDP port number to be used by the cipe process in both endpoints.

  • PEER=0.0.0.0, which specifies the real address of the remote cipe endpoint. You can set this address dynamically by setting this value to 0.0.0.0.

  • IPADDR=0.0.0.0, which specifies the virtual address at the local end of the cipe tunnel.

  • PTPADDR=0.0.0.0, which specifies the virtual address at the remote end of the cipe tunnel.

/etc/sysconfig/clock

The /etc/sysconfig/clock file controls the interpretation of values read from the system clock. Earlier releases of Red Hat Linux used the following values (which are deprecated):

  • CLOCKMODE=<value>, where <value> is one of the following:

    • GMT — Indicates that the clock is set to Universal Time (Greenwich Mean Time).

    • ARC — Indicates the ARC console's 42-year time offset is in effect (for Alpha-based systems only).

Currently, the correct values are:

  • UTC=<value>, where <value> is one of the following boolean values:

    • true — Indicates that the clock is set to Universal Time. Any other value indicates that it is set to local time.

  • ARC=<value>, where <value> is the following:

    • true — Indicates the ARC console's 42-year time offset is in effect. Any other value indicates that the normal UNIX epoch is assumed (for Alpha-based systems only).

  • ZONE=<filename> — Indicates the timezone file under /usr/share/zoneinfo that /etc/localtime is a copy of, such as:

    ZONE="America/New York"

/etc/sysconfig/desktop

The /etc/sysconfig/desktop file specifies the desktop manager to be run, such as:

DESKTOP="GNOME"

/etc/sysconfig/firewall

The /etc/sysconfig/firewall file contains various firewall settings. By default, this file is created but empty.

/etc/sysconfig/harddisks

The /etc/sysconfig/harddisks file allows you to tune your hard drive(s).

WarningWarning
 

Don't make changes to this file lightly. If you change the default values stored here, you could corrupt all of the data on your hard drive(s).

The /etc/sysconfig/harddisks file may contain the following:

  • USE_DMA=1, where setting this to 1 enables DMA. However, with some chipsets and hard drive combinations, DMA can cause data corruption. Check with your hard drive documentation or manufacturer before enabling this.

  • 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.

/etc/sysconfig/hwconf

The /etc/sysconfig/hwconf file lists all the hardware that kudzu detected on your 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 you do edit it, devices could suddenly show up as being added or removed.

/etc/sysconfig/i18n

The /etc/sysconfig/i18n file sets the default language, such as:

LANG="en_US"

/etc/sysconfig/init

The /etc/sysconfig/init file controls how the system will appear and function during bootup.

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. Defaults to ANSI sequences output by echo -e.

  • SETCOLOR_SUCCESS=<value>, where <value> sets the color to a color indicating success. Defaults to ANSI sequences output by echo -e, setting the color to green.

  • SETCOLOR_FAILURE=<value>, where <value> sets the color to a color indicating failure. Defaults to ANSI sequences output by echo -e, setting the color to red.

  • SETCOLOR_WARNING=<value>, where <value> sets the color to a color indicating warning. Defaults to ANSI sequences output by echo -e, setting the color to yellow.

  • SETCOLOR_NORMAL=<value>, where <value> sets the color to 'normal'. Defaults to ANSI sequences output by echo -e.

  • LOGLEVEL=<value>, where <value> sets the initial console logging level for the kernel. The default is 7; 8 means everything (including debugging); 1 means nothing except kernel panics. syslogd will override this once it starts.

  • 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.

/etc/sysconfig/irda

The /etc/sysconfig/irda file controls how infared devices on your system are configured at startup.

The following values may be used:

  • IRDA=<value>, where <value> is one of the following boolean values:

    • yesirattach 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 your system, this line must be set to yes.

    • noirattach 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.

/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 /usr/lib/kbd/keymaps/i386 and branch into different keyboard layouts from there, all labeled <file>.kmap.gz. The first file found beneath /usr/lib/kbd/keymaps/i386that matches the KEYTABLE setting is used.

/etc/sysconfig/kudzu

The /etc/sysconfig/kuzdu allows you to specify a safe probe of your system's hardware by kudzu at boot time. A safe probe is one that disables serial port and DDC monitor probing.

  • SAFE=<value>, where <value> is one of the following:

    • yeskuzdu does a safe probe.

    • nokuzdu does a normal probe.

/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:

    • 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.

In addition, /dev/mouse is a symbolic link that points to the actual mouse device.

/etc/sysconfig/network

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.domain.com, but can be whatever hostname you want.

    NoteNote
     

    For compatibility with older software that people might install (such as trn), the /etc/HOSTNAME file should contain the same value as 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.

/etc/sysconfig/pcmcia

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.

/etc/sysconfig/rawdevices

The /etc/sysconfig/rawdevices file is used to configure raw device bindings, such as:

/dev/raw/raw1 /dev/sda1
/dev/raw/raw2 8 5

/etc/sysconfig/sendmail

The /etc/sysconfig/sendmail file allows messages to be sent to one or more recipients, routing the message over whatever networks are necessary. The file sets the default values for the Sendmail application to run. Its default values are to run as a background daemon, and to check its queue once an hour in case something has backed up.

The following values may be used:

  • DAEMON=<value>, where <value> is one of the following boolean values:

    • yesSendmail should be configured to listen to port 25 for incoming mail. yes implies the use of Sendmail's -bd options.

    • noSendmail 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.

/etc/sysconfig/soundcard

The /etc/sysconfig/soundcard file is generated by sndconfig and should not be modified. The sole use of this file is to determine what card entry in the menu to pop up by default the next time sndconfig is run. Soundcard configuration information is located in the /etc/modules.conf file.

It may contain the following:

  • CARDTYPE=<value>, where <value> is set to, for example, SB16 for a Soundblaster 16 sound card.

/etc/sysconfig/ups

The /etc/sysconfig/ups file is used to specify information about any Uninterruptible Power Supplies (UPS) connected to your system. A UPS can be very valuable for a Red Hat Linux system because it gives you time to correctly shut down the system in the case of power interruption. The following values may be used:

  • SERVER=<value>, where <value> is one of the following:

    • yes — A UPS device is connected to your system.

    • no — A UPS device is not connected to your system.

  • MODEL=<value>, where <value> must be one of the following or set to NONE if no UPS is connected to the system:

    • apcsmart — For a APC SmartUPS™ or similar device.

    • fentonups — For a Fenton UPS™.

    • optiups — For an OPTI-UPS™ device.

    • bestups — For a Best Power™ UPS.

    • genericups — For a generic brand UPS.

    • ups-trust425+625 — For a Trust™ UPS.

  • DEVICE=<value>, where <value> specifies where the UPS is connected, such as /dev/ttyS0.

  • OPTIONS=<value>, where <value> is a special command that needs to be passed to the UPS.

/etc/sysconfig/vncservers

The /etc/sysconfig/vncservers file configures how the Virtual Network Computing (VNC) server starts up. VNC is a remote display system which allows you to view a desktop environment not only on the machine where it is running but across different networks (from a LAN to the Internet) and using a wide variety of machine architectures.

It may contain the following:

  • VNCSERVERS=<value>, where <value> is set to something like "1:root".

Files in /etc/sysconfig/network-scripts/

The following files are normally found in /etc/sysconfig/network-scripts, where <if-name> represents the name of the network interface:

Let's take a look at each one.

/etc/sysconfig/network-scripts/ifup and /etc/sysconfig/network-scripts/ifdown

These are symbolic links to /sbin/ifup and /sbin/ifdown, respectively. These are the only two scripts in this directory that should be called directly; these two scripts call all the other scripts as needed. These symbolic links are here for legacy purposes only — they will probably be removed in future versions, so only /sbin/ifup and /sbin/ifdown should currently be used.

These scripts normally take one argument: the name of the device (such as eth0). They are called with a second argument of boot during the boot sequence so that devices that are not meant to be brought up on boot (ONBOOT=no, [see below]) can be ignored at that time.

/etc/sysconfig/network-scripts/network-functions

Not really a public file. Contains functions which the scripts use for bringing interfaces up and down. In particular, it contains most of the code for handling alternative interface configurations and interface change notification through netreport, which is the program that tells network management scripts to send a SIGIO signal to the process which called netreport when any network interface status changes occur.

/etc/sysconfig/network-scripts/ifcfg-<if-name> and /etc/sysconfig/network-scripts/ifcfg-<if-name>:<clone-name>

The first file defines an interface, while the second file contains only the parts of the definition that are different in a "alias" (or alternative) interface. Both require that an <if-name> (name of a network interface) is specified. For example, the network numbers might be different but everything else might be the same, so only the network numbers would be in the clone file while all the device information would be in the base ifcfg file.

The items that can be defined in an ifcfg file depend on the interface type.

The following values are common:

  • DEVICE=<name>, where <name is the name of the physical device (except dynamically-allocated PPP devices where it is the "logical name").

  • IPADDR=<addr>, where <addr> is the IP address.

  • NETMASK=<mask>, where <mask> is the netmask value.

  • NETWORK=<addr>, where <addr> is the network address.

  • BROADCAST=<addr>, where <addr> is the broadcast address.

  • GATEWAY=<addr>, where <addr> is the gateway address.

  • ONBOOT=<answer>, where <answer> is one of the following:

    • yes — This device should be activated at boot-time.

    • no — This device should not be activated at boot-time.

  • USERCTL=<answer>, where <answer> is one of the following:

    • yes — Non-root users are allowed to control this device.

    • no — Non-root users are not allowed to control this device.

  • BOOTPROTO=<proto>, where <proto> is one of the following:

    • none — No boot-time protocol should be used.

    • bootp — The BOOTP protocol should be used.

    • dhcp — The DHCP protocol should be used.

The following values are common to all SLIP files:

  • PERSIST=<answer>, where <answer> is one of the following:

    • yes — This device should be kept active at all times, even if deactivated after a modem hang up.

    • no — This device should not be kept active at all times.

  • MODEMPORT=<port>, where <port> is the modem port's device name (for example, "/dev/modem").

  • LINESPEED=<baud>, where <baud> is the modem's linespeed (for example, "115200").

  • DEFABORT=<answer>, where <answer> is one of the following:

    • yes — Insert default abort strings when creating/editing the script for this interface.

    • no — Do not insert default abort strings when creating/editing the script for this interface.

/etc/sysconfig/network-scripts/chat-<if-name>

This file is a chat script for SLIP connections and is intended to establish the connection. For SLIP devices, a DIP script is written from the chat script.

/etc/sysconfig/network-scripts/ifup-post

This file is called when any network device (except a SLIP device) comes up. It calls /etc/sysconfig/network-scripts/ifup-routes to bring up static routes that depend on that device, brings up aliases for that device, and sets the hostname if it is not already set — and a hostname can be found for the IP for that device. ifup-post sends SIGIO to any programs that have requested notification of network events.

This file could be extended to set up name service configuration, call arbitrary scripts, and more, as needed.