SYSTEM(5,F) AIX Technical Reference SYSTEM(5,F)
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system
PURPOSE
Identifies the system devices.
DESCRIPTION
The system file contains entries for currently configured real devices and
virtual devices.
The system file is an attribute file containing stanzas that generally describe
special files including information about AIX drivers or system parameters.
See "attributes" for a description of attribute files.
Special File Stanzas
Each special file named in the system file refers to a device driver entry in
the master file. The driver entries specify the AIX device drivers to be
configured. All drivers needed for specified special files are included, and
those drivers marked as mandatory.
The name of each stanza is the simple name of the special file.
The use of extended characters in the system file is not supported.
address The device address for the virtual device (AIX/370 only).
aflag Not used.
arg The device's name and minor number for the corresponding disk or
minidisk where arg activities should be performed.
ctibuf Number of input buffers that should be available for the device
simultaneously.
ctobuf Number of output buffers that should be available for the device
simultaneously.
dname Indicates the prefix name that is used to create the name of the
device stanza in the /etc/system file and the special file in the
/dev directory. The devices command uses this value when it
creates a stanza name for a new special file.
driver Identifies the associated driver in the master file. This is
mandatory in all device stanzas.
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dtype Specifies the class of the device. Examples of this are printer
and disk. The devices command displays this value when asking the
user to choose a device class. It also uses this value to
construct a list of device classes.
dump The device's name and minor number for the corresponding disk or
minidisk where dump activities should be performed.
dumplow Location of the number of blocks into the dump partition where
core dump should be started.
features Device-dependent parameter which is interpreted by the device
driver on a device-by-device basis (refer to description of
individual device).
fd The name of the fixed disk that the minidisk resides on, such as
hdisk0 and hdisk1. Used by minidisks.
file Identifies the file that contains the stanzas included by the use
attribute. This is the /etc/ddi file associated with the device.
files Maximum number of entries in the system file table.
gmounts Number of different file systems that can be mounted in the same
cluster simultaneously.
kaf_file Indicates the name of the keyword attribute file to be used by the
customization helper programs for the device described in the
device stanza.
kaf_use Indicates the name of the stanza in the kaf_file that contains
information about the attributes for the device.
locsite Specifies the cluster site number.
minor Has a value of the form cn, where c is either b to denote a block
device, or c to denote a character device. n is the minor device
number.
modes Sets the protection bits for the special file, specified in the
form rwxrwxrwx. Hyphens replace modes that are turned off, for
example, "rw-r--r--".
mounts Not used.
name Is a required keyword that identifies the device type. For
example, 4202, 4201 for printers.
nchann Number of AIX/370 channels.
nob Number of Blocks - used by minidisks
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noddi Indicates whether any device-dependent information is associated
with the device. The value TRUE indicates there is none. If
noddi=TRUE, then the change subcommand of the devices command does
not allow the user to change device characteristics. Although
tape, Ethernet, and Token Ring have ddi files, noddi indicates
that there is no information in them.
nodelete Indicates whether to delete the special file when this driver is
removed. When this value is TRUE, no attempt is made to delete
the special file.
nodl Indicates whether the device can be deleted from the system by the
devices command. The value TRUE indicates the device cannot be
deleted using this command.
noduplicate Indicates whether another device of this type can be added to the
system. The value TRUE indicates another device cannot be added.
noipl Indicates whether this stanza is processed at initial program load
(IPL) time. When this value is TRUE, this stanza is not processed
at system initial program load (IPL) time.
noshow Indicates whether the devices command displays information from
the stanza to the user. If noshow=FALSE, then the showdev
subcommand of the devices command displays all device
characteristics and the showall subcommand displays the device.
nospecial When this value is TRUE, no special file (/dev file) is to be
created.
owner Specifies the name of the owner assigned to the /dev special file
when it is created.
par A required keyword for printer stanzas. Indicates if the printer
attaches to a parallel (TRUE) or serial (FALSE) port.
pflag Is a required keyword that indicates whether there is a port
associated with the device. If the value is TRUE, then the
devices command constructs the name of the ddi stanza when adding
the device by concatenating the value of the use keyword and the
port name.
If FALSE, then devices constructs the name of the ddi stanza by
concatenating the value of the use keyword and a port number. A
maxminor keyword must be defined if the value of pflag is FALSE.
The showall subcommand of the devices command displays the comment
line that immediately follows the aflag definition as a
description of the port. This comment line must have the same
length as those that describe the relevant ports in the ports
stanza.
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pipe The device's name and minor number for the corresponding disk or
minidisk where pipe activities should be performed.
port A required keyword for all stanzas with pflag set to TRUE. When
port is used in an /etc/predefined stanza, it defines the range of
valid ports for this device, like port ranges specified for
adapters in the adapts stanza.
When a device, that is assigned a port, is added to /etc/system,
devices removes the port range from the right side of the equal
sign and replaces it with a port number in the port range.
root The device's name and minor number for the corresponding disk or
minidisk where root activities should be performed.
slot Defines the slot number associated with a device. When defined in
/etc/predefined, slot must be set to 0 if pflag is TRUE or --- if
pflag is FALSE. If pflag is TRUE, devices will assign slot a
valid slot number when adding the stanza to /etc/system.
specproc Indicates the name of the special processing routine that is to be
invoked when customizing the system for the device. See "cfgadev"
for information about the application program interface to this
feature.
swap The device's name and minor number for the corresponding disk or
minidisk where swap activities should be performed.
ttype Specifies the value to be used by config in the device-type field
when building device configuration table for devices. When
present, ttype overrides the contents of the drive value.
uinfo Specifies the hexadecimal bytes to pass to the CFUDRV type ioctl
call to configure an AIX device driver. If a customization helper
program is invoked, this attribute is not used.
units Number of devices; the number must be specified for each type of
device available.
use Identifies a stanza to be logically included in the current
stanza. If a file attribute is present, the file is searched to
find the indicated stanza for device dependent information. This
keyword is required if the file keyword is present.
vbuf Not used.
System Parameter Stanzas
All system parameters that are listed in /etc/master may have their default
values overridden in the sysparms stanza. The format of system parameter
keywords in sysparms is:
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parm = value
Where:
parm Is a stanza name of a system parameter stanza in /etc/master
value Is the new value of the system parameter
Refer to /etc/master for a definition of all system parameters.
Other parameters can be given for special customization helper programs.
EXAMPLE
The following is an excerpt of the system file entries:
Smallest possible stanza:
error:
driver = err
nospecial = true
noshow = true
Sample stanza with pflag set to false
tokennet0:
* Token Ring Device Driver
name = token
driver = token
minor = c0
kaf_file = /etc/ddi/token
kaf_use = ktoken
file = /etc/ddi/token
noddi = true
dtype = lan
* Local Area Network
pflag = false
* Token Ring Device Driver
modes = rw-rw-rw-
noshow = false
slot = ---
nospecial = true
specproc = /etc/lanspecial
owner = root
dname = tokennet0
use = dtokennet0
Sample stanza with pflag set to true (tty connected to a Dual Async
Adapter port):
tty0:
* Asynchronous Terminal
name = tty
driver = sa
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minor = c0
kaf_file = /etc/ddi/tty.kaf
kaf_use = ktty
file = /etc/ddi/tty
noddi = true
noduplicate = false
dtype = ttydev
* Asynchronous Terminal
specproc = cfgaport
noshow = false
pflag = true
* Serial port 1
port = s1
slot = 03
noipl = false
modes = rw-rw-rw-
owner = root
dname = tty0
use = dttys1
FILE
/etc/system
RELATED INFORMATION
In this book: "attributes," "ddi," "master," and "predefined."
The config, devices, and osconfig commands in AIX Operating System Commands
Reference.
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