sysconfigtab - Configurable subsystem definition database
The sysconfigtab file contains initial values for the
attributes of subsystems that can be dynamically configured.
The information in the sysconfigtab file is loaded
into an in-memory kernel database when the system boots.
At subsystem configuration time, values in the in-memory
kernel database override default values coded into the
There are multiple numbered versions of the sysconfigtab.*
file in the /etc directory, but only the /etc/sysconfigtab
version is used during normal operations. The versions are
present to support the dynamic linking of modules to create
a /vmunix kernel. This feature is called bootlinking
and is documented in Guide to Preparing Product Kits. You
may not be able to use bootlinking if you delete any
copies of the sysconfigtab.* file.
Avoid making manual changes to this file. Instead, use
the command sysconfigdb(8) to make changes. This utility
will automatically make any changes available to the kernel
and will preserve the structure of the file so that
future upgrades will merge in correctly.
The sysconfigtab file consists of formatted entries. The
first line in an entry specifies the subsystem name. Subsequent
lines specify the subsystems' attributes and values.
Comment lines are allowed within an entry. The following
shows the syntax of a subsystem entry: subsystem-name:
#This is a comment describing the subsystem
attribute1 = value1
attribute2 = value2, value3
The following list details sysconfigtab entries: The subsystem
name is terminated with a colon (:). Each
attribute name and value pair are terminated with a newline
character. Attribute names are separated from values
with an equal sign (=). No space is allowed in the middle
of an attribute name, including an array attribute name.
For instance, array attribute names such as attr1 and
attr1 are permitted, but attr1  or attr1[ 2 ] are
not. For example, the following line in /etc/sysconfigtab
attr1 = 2 Attributes that have more than one
value separate the values with a comma (,). Quotation
marks are not used (") in string values. Blank
or tab characters may occur in the middle of a
string, but leading or trailing blanks are ignored.
A number sign (#) appears at the beginning of comment
Comments that are specific to the subsystem are
placed after the line containing the subsystem
name. The sysconfigdb command considers a sysconfigtab
entry to begin with the subsystem name and
end with either the next subsystem name or the end
of the file. Any comments that appear before a
subsystem name are considered to be part of the
preceding subsystem and are deleted if the preceding
subsystem is deleted.
For a list of the subsystem attributes you can configure,
see the System Administration manual. Refer also to the
various sys_attrs reference pages, which list the system
attributes and their default or maximum values. The graphical
user interface dxkerneltuner provides you with an
easy way to review and adjust attribute values.
For information about loadable device driver attributes,
see the Writing Device Drivers: Tutorial manual.
In a cluster environment, an additional clusterwide file,
sysconfigtab.cluster, is used to contain those attributes
that must be set to the same values in each member's
/etc/sysconfigtab file. When a cluster member boots, the
contents of its /etc/sysconfigtab file is synchronized
against the clusterwide sysconfigtab.cluster file.
The maximum length of a stanza entry is 40960 bytes. An
entry cannot contain more than 2048 fields (lines).
The maximum length of a stanza field is 500 bytes.
The following shows an example stanza entry that could
appear in the configurable subsystem database:
max-proc-per-user = 64
max-threads-per-user = 256
The preceding entry defines the max-proc-per-user and maxthreads-per-user
attributes for the proc subsystem.
Commands: dxkerneltuner(8), sys_attrs(5), sysconfig(8),
Writing Device Drivers: Tutorial
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