UTMPD(8) Maintenance Commands and Procedures UTMPD(8)

NAME

utmpd - utmpx monitoring daemon

SYNOPSIS

utmpd [-debug]

DESCRIPTION

The utmpd daemon monitors the /var/adm/utmpx file. See utmpx(5) (and
utmp(5) for historical information).


utmpd receives requests from pututxline(3C) by way of a named pipe.
It maintains a table of processes and uses poll(2) on /proc files to
detect process termination. When utmpd detects that a process has
terminated, it checks that the process has removed its utmpx entry
from /var/adm/utmpx. If the process' utmpx entry has not been
removed, utmpd removes the entry. By periodically scanning the
/var/adm/utmpx file, utmpd also monitors processes that are not in
its table.

OPTIONS

-debug

Run in debug mode, leaving the process connected to the
controlling terminal. Write debugging information to standard
output.

EXIT STATUS

The following exit values are returned:

0

Successful completion.


>0

An error occurred.

FILES

/etc/default/utmpd

You can set default values for the flags listed below. For
example: SCAN_PERIOD=600

The values for these flags should be greater than 0. If values
read from the file are found to be less than or equal to 0, or
containing invalid characters, the default values mentioned below
are retained.

SCAN_PERIOD

The number of seconds that utmpd sleeps between checks of
/proc to see if monitored processes are still alive. The
default is 300.


MAX_FDS

The maximum number of processes that utmpd attempts to
monitor. The default value is 4096.


WTMPX_UPDATE_FREQ

The number of seconds that utmpd sleeps between read accesses
of the wtmpx file. The wtmpx file's last access time is used
by init(8) on reboot to determine when the operating system
became unavailable. The default is 60.


/var/adm/utmpx

File containing user and accounting information for commands such
as who(1), write(1), and login(1).


/proc

Directory containing files for processes whose utmpx entries are
being monitored.

SEE ALSO

svcs(1), poll(2), pututxline(3C), proc(5), utmp(5), utmpx(5),
attributes(7), smf(7), init(8), svcadm(8)

NOTES

If the filesystem holding /var/adm/wtmpx is mounted with options
which inhibit or defer access time updates, an unknown amount of
error will be introduced into the utmp DOWN_TIME record's timestamp
in the event of an uncontrolled shutdown (for example, a crash or
loss of power). Controlled shutdowns will update the modify time of
/var/adm/wtmpx, which will be used on the next boot to determine when
the previous shutdown occurred, regardless of access time deferral or
inhibition.


The utmpd service is managed by the service management facility,
smf(7), under the service identifier:

svc:/system/utmp:default


Administrative actions on this service, such as enabling, disabling,
or requesting restart, can be performed using svcadm(8). The
service's status can be queried using the svcs(1) command.

February 17, 2023 UTMPD(8)