Bug 1117704

Summary: SHM refclock doesn't support nanosecond resolution
Product: Red Hat Enterprise Linux 6 Reporter: Miroslav Lichvar <mlichvar>
Component: ntpAssignee: Miroslav Lichvar <mlichvar>
Status: CLOSED ERRATA QA Contact: Jakub Prokes <jprokes>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 6.6CC: jprokes, kdube, ovasik, psklenar, qe-baseos-daemons
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: ntp-4.2.6p5-3.el6 Doc Type: Enhancement
Doc Text:
Support for nanosecond resolution has been added to the SHM reference clock. Prior to this update, when a Precision Time Protocol (PTP) hardware clock was used as a time source to synchronize the system clock (for example, with the timemaster service from the linuxptp package), the accuracy of the synchronization was limited due to the microsecond resolution of the SHM protocol. The nanosecond extension in the SHM protocol now enables sub-microsecond synchronization of the system clock.
 Story Points: ---
Clone Of: 1117702 Environment:
Last Closed: 2015-07-22 06:59:53 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1117702    
Bug Blocks: 1085584, 1095797, 1159824, 1159926    

Description Miroslav Lichvar 2014-07-09 08:43:21 UTC 
Description of problem:
The SHM refclock in ntpd is limited to microsecond resolution. In 4.2.7 development a nanosecond extension was added to the protocol. This can be useful to improve accuracy of the synchronization with PTP clocks and phc2sys from linuxptp.

https://bugs.ntp.org/show_bug.cgi?id=1232

Version-Release number of selected component (if applicable):
4.2.6p5-1
Comment 4 errata-xmlrpc 2015-07-22 06:59:53 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2015-1459.html