NTPTIME(8) BSD System Manager's Manual NTPTIME(8)NAME
ntptime -- read kernel time variables
SYNOPSIS
ntptime [-chr] [-e est_error] [-f frequency] [-m max_error] [-o offset] [-s status] [-t time_constant]
DESCRIPTION
This program is useful only with special kernels described in the A Kernel Model for Precision Timekeeping page in
/usr/share/doc/html/ntp/kern.html. It reads and displays time-related kernel variables using the ntp_gettime(2) system call. A similar dis-
play can be obtained using the ntpdc program and kerninfo command.
OPTIONS -c Display the execution time of ntptime itself.
-e est_error
Specify estimated error, in microseconds.
-f frequency
Specify frequency offset, in parts per million.
-h Display times in Unix timeval format. Default is NTP format.
-l Specify the leap bits as a code from 0 to 3.
-m max_error
Display help information.
-o offset
Specify clock offset, in microseconds.
-r Display Unix and NTP times in raw format.
-s status
Specify clock status. Better know what you are doing.
-t time_constant
Specify time constant, an integer in the range 0-4.
AUTHORS
David L. Mills (mills@udel.edu)
BSD March 29, 2000 BSD
Check Out this Related 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-r5tickadj(1)