DWS/chrony
1
0
Fork 0
mirror of https://gitlab.com/chrony/chrony.git synced 2025-12-07 11:25:08 -05:00
Code Issues Packages Projects Releases Wiki Activity

doc: update chrony description

Browse Source
This commit is contained in:
Miroslav Lichvar
2015-04-24 10:46:52 +02:00
parent f72016a78e
commit bbf4c3186b
2 changed files with 44 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
chrony.texi.in
View File

@@ -56,34 +56,30 @@ Copyright @copyright{} 2009-2014 Miroslav Lichvar
@c {{{ S:Overview
@node Overview
@section Overview
Chrony is a software package for maintaining the accuracy of computer
system clocks. It consists of a pair of programs :
chrony is a versatile implementation of the Network Time Protocol (NTP).
It can synchronize the system clock with NTP servers, reference clocks
(e.g. GPS receiver), and manual input using wristwatch and keyboard.
It can also operate as an NTPv4 (RFC 5905) server and peer to provide
a time service to other computers in the network.
@itemize @bullet
@item @code{chronyd}. This is a daemon which runs in background on the
system. It obtains measurements (e.g. via the network) of the system's
offset relative to other systems, and adjusts the system time
accordingly. For isolated systems, the user can periodically enter the
correct time by hand (using @code{chronyc}). In either case,
@code{chronyd} determines the rate at which the computer gains or loses
time, and compensates for this.
It is designed to perform well in a wide range of conditions, including
intermittent network connections, heavily congested networks, changing
temperatures (ordinary computer clocks are sensitive to temperature),
and systems that do not run continuosly, or run on a virtual machine.
@code{chronyd} can also act as an NTP server, and provide a time-of-day service
to other computers. A typical set-up is to run @code{chronyd} on a gateway
computer that has a dial-up link to the Internet, and use it to serve time to
computers on a private LAN sitting behind the gateway. The IP addresses that
can act as clients of @code{chronyd} can be tightly controlled. The default is
no client access.
Typical accuracy between two machines on a LAN is in tens, or a few
hundreds, of microseconds; over the Internet, accuracy is typically
within a few milliseconds. With a good hardware reference clock
sub-microsecond accuracy is possible.
@item @code{chronyc}. This is a command-line driven control and
monitoring program. An administrator can use this to fine-tune various
parameters within the daemon, add or delete servers etc whilst the
daemon is running.
Two programs are included in chrony, @code{chronyd} is a daemon that can
be started at boot time and @code{chronyc} is a command-line interface
program which can be used to monitor @code{chronyd}'s performance and to
change various operating parameters whilst it is running.
The IP addresses from which @code{chronyc} clients may connect can be tightly
controlled. The default is just the computer that @code{chronyd} itself is
running on.
@end itemize
@c }}}
@c {{{ S:Acknowledgments
@node Acknowledgements