tickadj(1) [suse man page]

tickadj(1)						      General Commands Manual							tickadj(1)

NAME

       tickadj - set time-related kernel variables

SYNOPSIS

       tickadj [ -Aqs ] [ -a tickadj  ] [ -t tick  ]

DESCRIPTION

       The  tickadj   program  reads,  and  optionally modifies, several timekeeping-related variables in the running kernel in some machines, via
       /dev/kmem . The particular variables it is concerned with are tick , which is the number of microseconds added to the system time during  a
       clock  interrupt,  tickadj  , which sets the slew rate and resolution used by the adjtime  system call, and dosynctodr , which indicates to
       the kernels on some machines whether they should internally adjust the system clock to keep it in line with time-of-day clock or not.

       By default, with no arguments, tickadj  reads the variables of interest in the kernel and displays them. At the same time, it determines an
       "optimal" value for the value of the tickadj  variable if the intent is to run the ntpd Network Time Protocol (NTP) daemon, and prints this
       as well. Since the operation of tickadj	when reading the kernel mimics the operation of similar parts of the ntpd  program fairly closely,
       this can be useful when debugging problems with ntpd .

       Note  that tickadj  should be run with some caution when being used for the first time on different types of machines. The operations which
       tickadj	tries to perform are not guaranteed to work on all Unix machines and may in rare cases cause the kernel to crash.

COMMAND LINE OPTIONS

       -a      tickadj Set the kernel variable tickadj	to the value tickadj  specified.

       -A      Set the kernel variable tickadj	to an internally computed "optimal" value.

       -t      tick Set the kernel variable tick  to the value tick   specified.

       -s      Set the kernel variable dosynctodr  to zero, which disables the hardware time-of-year clock, a prerequisite for	running  the  ntpd
	       daemon under SunOS4.

       -q      Normally, tickadj  is quite verbose about what it is doing. The -q  flag tells it to shut up about everything except errors.

FILES

       /vmunix

       /unix

       /dev/kmem

BUGS

       Fiddling  with  kernel  variables at run time as a part of ordinary operations is a hideous practice which is only necessary to make up for
       deficiencies in the implementation of adjtime  in many kernels and/or brokenness of the system clock in some vendors' kernels. It would	be
       much better if the kernels were fixed and the tickadj  program went away.

SEE ALSO

       More documentation is available in the package ntp-doc.

AUTHOR

       David L. Mills <mills@udel.edu>

ntp 4.1.1b-r5																tickadj(1)

Check Out this Related Man Page

NTPD(8) 						      System Manager's Manual							   NTPD(8)

NAME

       ntpd - "Network Time Protocol daemon"

SYNOPSIS

       ntpd [-dnSsv] [-f file]

DESCRIPTION

       The  ntpd  daemon  synchronizes	the local clock to one or more remote NTP servers or local timedelta sensors.  ntpd can also act as an NTP
       server itself, redistributing the local time.  It implements the Simple Network Time Protocol version 4, as described in RFC 2030, and  the
       Network Time Protocol version 3, as described in RFC 1305.

       ntpd uses the adjtime(2) system call to correct the local system time without causing time jumps.  Adjustments larger than 128ms are logged
       using syslog(3) with LOG_INFO priority.	The threshold value is chosen to avoid having local clock drift thrash the log files.  Should ntpd
       be started with the -d option, all calls to adjtime(2) will be logged.

       When ntpd starts up, it reads settings from a configuration file, typically ntpd.conf(5).

       The options are as follows:

       -d     Do not daemonize.  If this option is specified, ntpd will run in the foreground and log to stderr.

       -f file
	      Use file as the configuration file, instead of the default /etc/openntpd/ntpd.conf.

       -n     Configtest mode.	Only check the configuration file for validity.

       -S     Do not set the time immediately at startup.  This is the default.

       -s     Set  the time immediately at startup if the local clock is off by more than 180 seconds.	Allows for a large time correction, elimi-
	      nating the need to run rdate(8) before starting .

       -v     This option allows ntpd to send DEBUG priority messages to syslog.

	      When ntpd receives a SIGINFO signal, it will write its peer and sensor status to syslog.

FILES

       /etc/openntpd/ntpd.conf
	      default ntpd configuration file

       /var/lib/openntpd/ntpd.drift
	      drift file, written by ntpd periodically and used at startup to get the initial clock drift

SEE ALSO

       date(1), adjfreq(2), adjtime(2), ntpd.conf(5), rdate(8), timed(8)

       , Network Time Protocol (Version 3), March 1992.

       , Simple Network Time Protocol (SNTP) Version 4, October 1996.

HISTORY

       The ntpd program first appeared in OpenBSD 3.6 .

							   $Mdocdate: November 10 2007 $						   NTPD(8)

Linux and UNIX Man Pages

tickadj(1) [suse man page]

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