| This is the README for chrony. |
| |
| What is chrony? |
| =============== |
| |
| chrony is a versatile implementation of the Network Time Protocol (NTP). |
| It can synchronise 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. |
| |
| 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. |
| |
| Typical accuracy between two machines synchronised over the Internet is |
| within a few milliseconds; on a LAN, accuracy is typically in tens of |
| microseconds. With hardware timestamping, or a hardware reference clock, |
| sub-microsecond accuracy may be possible. |
| |
| Two programs are included in chrony, chronyd is a daemon that can be |
| started at boot time and chronyc is a command-line interface program |
| which can be used to monitor chronyd's performance and to change various |
| operating parameters whilst it is running. |
| |
| What will chrony run on? |
| ======================== |
| |
| The software is known to work on Linux, FreeBSD, NetBSD, macOS and |
| illumos. Closely related systems may work too. Any other system will |
| likely require a porting exercise. |
| |
| How do I set it up? |
| =================== |
| |
| The file INSTALL gives instructions. On supported systems the |
| compilation process should be automatic. You will need a C compiler, |
| e.g. gcc or clang. |
| |
| What documentation is there? |
| ============================ |
| |
| The distribution includes manual pages and a document containing |
| Frequently Asked Questions (FAQ). |
| |
| The documentation is also available on the chrony web pages, accessible |
| through the URL |
| |
| https://chrony.tuxfamily.org/ |
| |
| Where are new versions announced? |
| ================================= |
| |
| There is a low volume mailing list where new versions and other |
| important news relating to chrony are announced. You can join this list |
| by sending mail with the subject "subscribe" to |
| |
| chrony-announce-request@chrony.tuxfamily.org |
| |
| How can I get support for chrony? |
| ================================= |
| |
| There are two other mailing lists relating to chrony. chrony-users is a |
| discussion list for users, e.g. for questions about chrony configuration |
| and bug reports. chrony-dev is a more technical list for developers, |
| e.g. for submitting patches and discussing how new features should be |
| implemented. To subscribe to either of these lists, send a message with |
| the subject "subscribe" to |
| |
| chrony-users-request@chrony.tuxfamily.org |
| or |
| chrony-dev-request@chrony.tuxfamily.org |
| |
| as applicable. |
| |
| License |
| ======= |
| |
| chrony is distributed under the GNU General Public License version 2. |
| |
| Authors |
| ======= |
| |
| Richard P. Curnow <rc@rc0.org.uk> |
| Miroslav Lichvar <mlichvar@redhat.com> |
| |
| Acknowledgements |
| ================ |
| |
| In writing the chronyd program, extensive use has been made of the NTPv3 (RFC |
| 1305) and NTPv4 (RFC 5905) specification. The source code of the xntpd/ntpd |
| implementation written by Dennis Fergusson, Lars Mathiesen, David Mills, and |
| others has been used to check the details of the protocol. |
| |
| The following people have provided patches and other major contributions |
| to chrony: |
| |
| Lonnie Abelbeck <lonnie@abelbeck.com> |
| Benny Lyne Amorsen <benny@amorsen.dk> |
| Andrew Bishop <amb@gedanken.demon.co.uk> |
| Vincent Blut <vincent.debian@free.fr> |
| Stephan I. Boettcher <stephan@nevis1.columbia.edu> |
| David Bohman <debohman@gmail.com> |
| Goswin Brederlow <brederlo@informatik.uni-tuebingen.de> |
| Leigh Brown <leigh@solinno.co.uk> |
| Erik Bryer <ebryer@spots.ab.ca> |
| Jonathan Cameron <jic23@cam.ac.uk> |
| Bryan Christianson <bryan@whatroute.net> |
| Juliusz Chroboczek <jch@pps.jussieu.fr> |
| Kamil Dudka <kdudka@redhat.com> |
| Christian Ehrhardt <christian.ehrhardt@canonical.com> |
| Paul Elliott <pelliott@io.com> |
| Robert Fairley <rfairley@redhat.com> |
| Stefan R. Filipek <srfilipek@gmail.com> |
| Mike Fleetwood <mike@rockover.demon.co.uk> |
| Alexander Gretencord <arutha@gmx.de> |
| Andrew Griffiths <agriffit@redhat.com> |
| Walter Haidinger <walter.haidinger@gmx.at> |
| Juergen Hannken-Illjes <hannken@eis.cs.tu-bs.de> |
| John Hasler <john@dhh.gt.org> |
| Tjalling Hattink <t.hattink@fugro.nl> |
| Liam Hatton <me@liamhatton.com> |
| Jachym Holecek <jakym@volny.cz> |
| Håkan Johansson <f96hajo@chalmers.se> |
| Jim Knoble <jmknoble@pobox.com> |
| Antti Jrvinen <costello@iki.fi> |
| Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
| Eric Lammerts <eric@lammerts.org> |
| Stefan Lucke <stefan@lucke.in-berlin.de> |
| Victor Lum <viclum@vanu.com> |
| Kevin Lyda <kevin@ie.suberic.net> |
| Paul Menzel <paulepanter@users.sourceforge.net> |
| Vladimir Michl <vladimir.michl@seznam.cz> |
| Victor Moroz <vim@prv.adlum.ru> |
| Kalle Olavi Niemitalo <tosi@stekt.oulu.fi> |
| Frank Otto <sandwichmacher@web.de> |
| Denny Page <dennypage@me.com> |
| Chris Perl <cperl@janestreet.com> |
| Gautier PHILIPPON <gautier.philippon@ensimag.grenoble-inp.fr> |
| Andreas Piesk <apiesk@virbus.de> |
| Baruch Siach <baruch@tkos.co.il> |
| Foster Snowhill <forst@forstwoof.ru> |
| Andreas Steinmetz <ast@domdv.de> |
| NAKAMURA Takumi <takumi@ps.sakura.ne.jp> |
| Timo Teras <timo.teras@iki.fi> |
| Bill Unruh <unruh@physics.ubc.ca> |
| Stephen Wadeley <swadeley@redhat.com> |
| Bernhard Weiss <lisnablagh@web.de> |
| Wolfgang Weisselberg <weissel@netcologne.de> |
| Bernhard M. Wiedemann <bwiedemann@suse.de> |
| Joachim Wiedorn <ad_debian@joonet.de> |
| Ralf Wildenhues <Ralf.Wildenhues@gmx.de> |
| Ulrich Windl <ulrich.windl@rz.uni-regensburg.de> |
| Michael Witten <mfwitten@gmail.com> |
| Doug Woodward <dougw@whistler.com> |
| Thomas Zajic <zlatko@zlatko.fdns.net> |
| |
| Many other people have contributed bug reports and suggestions. We are sorry |
| we cannot identify all of you individually. |
