sys_attrs(5)							File Formats Manual						      sys_attrs(5)

NAME

       sys_attrs - introduction to kernel subsystem attributes used for configuration and tuning

DESCRIPTION

       The  operating  system  kernel is built from many mandatory and optional subsystems. If you are logged into the root account, the following
       command lists the subsystems included in the kernel for your system: # /sbin/sysconfig -s

       The majority of the kernel subsystems have sets of attributes whose values control different aspects of subsystem  configuration.  You  can
       examine	the names, the current settings, and (if applicable) the minimum, and maximum settings of attributes for a particular subsystem by
       using the /sbin/sysconfig command. The -q option followed by the subsystem name displays attribute  names  and  current	settings.  The	-Q
       option followed by the subsystem name displays minimum and maximum settings and the kinds of operations permitted on the attribute (Config-
       urable (at boot time), Reconfigurable (at run time), Query only). In the Common Desktop Environment (CDE), you can  run	the  dxkerneltuner
       application to get the same information.

									 Caution

       A  relatively  small number of the attributes listed in displays from these interfaces should actually be changed through these same inter-
       faces and then only as part of the system configuration and tuning tasks done by an experienced system or network administrator.  The  set-
       ting  of  most subsystem attributes should be done indirectly through system and network setup applications or be automatically adjusted by
       the kernel. This fact is very important to remember because attribute settings  can  have  complex  interrelationships  with  one  another,
       requiring  (in  some cases) careful manipulation of an entire set of attributes rather than only one. Furthermore, default settings of some
       subsystem attributes should never be touched, except by support personnel or by an administrator acting on instructions from  support  per-
       sonnel or patch kit documentation.

       Some  attributes  are  modifiable  at  run  time  for  ease of system tuning.  Others are modifiable at run time only because of a software
       requirement and should not be changed manually. In general, do not change the default value of any system  attribute  manually  unless  the
       system documentation or your support representative provides directions for changing it.

       Some  attributes have corresponding parameters in the system configuration file. If so, the corresponding parameter name in the system con-
       figuration file is specified in parentheses following the attribute name. In these cases, never	edit  the  system  configuration  file	to
       directly  change the value of the system parameter; use the dxkerneltuner application or the /sbin/sysconfig -r command to change the value
       of the attribute. For some subsystems, these values are best applied through a stanza-formatted file that is specified as  a  parameter	to
       the sysconfigdb command.

       See dxkerneltuner(8), sysconfig(8), and sysconfigdb(8) for more information about your options for configuring kernel subsystems.

       The following subsystems must be included when the kernel is built: Configuration Manager (cm) Generic Kernel (generic) Interprocess Commu-
       nication (ipc) Process (proc) Virtual File System (vfs) Virtual Memory (vm)

       A kernel also includes a processor-specific subsystem whose name is an internal code for a particular processor. Processor-specific subsys-
       tems typically have no attributes, are not modified directly by users, and are not documented.

       Other  kernel  subsystems are technically optional, although a kernel almost always includes quite a few optional subsystems in order for a
       system to be useful. For information on the attributes for a particular subsystem, refer to the reference  page	for  that  subsystem.  The
       names  of  these  reference  pages  adhere  to  the  format sys_attrs_subsystem-name. For example, to see the reference page that lists and
       describes attributes for the generic subsystem, you can type man sys_attrs_generic at the system command line.

       For guidelines on changing kernel subsystem attributes to improve system performance, see the System Configuration and Tuning  manual.  Any
       discussion  about  changing attributes for reasons other than tuning is located in the appropriate administration or program debugging man-
       ual.

       You can adjust some subsystem attribute values at run time. If so, the attribute descriptions mention that fact. To make it easy for you to
       locate these attributes when scanning lists, an asterisk (*) also precedes the names of these attributes.

SEE ALSO

       Commands: dxkerneltuner(8), sysconfig(8), sysconfigdb(8)

       Others: sys_attrs_cm(5), sys_attrs_generic(5), sys_attrs_ipc(5), sys_attrs_proc(5), sys_attrs_vfs(5), sys_attrs_vm(5)

       This  list  includes only reference pages for technically required subsystems.  The number of subsystems that can be configured in a kernel
       is very large, so all system attribute reference pages are not listed here.

       System Configuration and Tuning

       System Administration

       Network Administration

       Kernel Debugging

																      sys_attrs(5)