chrony配置介绍

rhel7 文档https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/sect-Using_chrony.html

https://wiki.archlinux.org/index.php/Chrony

Note: systemd-timesyncd.service is in conflict with chrony, so you need to disable it first if you want to enable chrony properly.

SERVER1:

[root@r10o10405.sqa.zmf /home/ahao.mah]
#chronyc sources
210 Number of sources = 1
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* 10.210.208.8                  4   6   377     9   +398us[ +652us] +/-   64ms

#cat /etc/chrony.conf
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst
server 10.210.208.8 iburst

# Ignore stratum in source selection.
stratumweight 0

# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

# Enable kernel RTC synchronization.
rtcsync

# In first three updates step the system clock instead of slew
# if the adjustment is larger than 10 seconds.
# 如果误差大于10s，前3次update时间使用step而不是slew
makestep 10 3

# Allow NTP client access from local network.
#allow 192.168/16

allow  192.168.0.0/16
allow  172.16.0.0/14
allow  10.0.0.0/8
allow  11.0.0.0/8
allow  30.0.0.0/8
#allow 10.101.75.1/22
#allow 10.101.75.1

#allow  100.64.0.0 mask 255.192.0.0

# Listen for commands only on localhost.
bindcmdaddress 127.0.0.1
bindcmdaddress ::1

# Serve time even if not synchronized to any NTP server.
local stratum 10

keyfile /etc/chrony.keys

# Specify the key used as password for chronyc.
commandkey 1

# Generate command key if missing.
generatecommandkey

# Disable logging of client accesses.
noclientlog

# Send a message to syslog if a clock adjustment is larger than 0.5 seconds.
logchange 0.5

logdir /var/log/chrony
#收集日志
log measurements statistics tracking

client

[root@r10o07276.sqa.zmf /home/ahao.mah]
#cat /etc/chrony.conf
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst
server 10.101.74.139  iburst
server 10.101.74.131  iburst

# Ignore stratum in source selection.
stratumweight 0

# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

# Enable kernel RTC synchronization.
rtcsync

# In first three updates step the system clock instead of slew
# if the adjustment is larger than 10 seconds. 简单说，如果误差大于10s，在头3次的时间更新中，会使用step，而不是slew
makestep 10 3  

#makestep 1000 10
#简单说，如果误差大于1000s，在头10次的时间更新中，会使用step，而不是slew
#This would step the system clock if the adjustment is larger than 1000 seconds, but only in the first ten clock updates. 

# Allow NTP client access from local network.
#allow 192.168/16

# Listen for commands only on localhost.
bindcmdaddress 127.0.0.1
bindcmdaddress ::1

# Serve time even if not synchronized to any NTP server.
local stratum 10

keyfile /etc/chrony.keys

# Specify the key used as password for chronyc.
commandkey 1

# Generate command key if missing.
generatecommandkey

# Disable logging of client accesses.
noclientlog

# Send a message to syslog if a clock adjustment is larger than 0.5 seconds.
logchange 0.5

logdir /var/log/chrony
#log measurements statistics tracking

命令

client

[[root@r10o07276.sqa.zmf /home/ahao.mah]
#chronyc sources
210 Number of sources = 2
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* r10o07413.sqa.zmf.tbsite.     5   6   377    64   -415us[ -274us] +/-   62ms
^+ r10o10405.sqa.zmf.tbsite.     5   6   377     1   -947us[ -947us] +/-   63ms

[root@r10o07276.sqa.zmf /home/ahao.mah]
#chronyc sources -v
210 Number of sources = 2

  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.
 / .- Source state '*' = current synced, '+' = combined , '-' = not combined,
| /   '?' = unreachable, 'x' = time may be in error, '~' = time too variable.
||                                                 .- xxxx [ yyyy ] +/- zzzz
||      Reachability register (octal) -.           |  xxxx = adjusted offset,
||      Log2(Polling interval) --.      |          |  yyyy = measured offset,
||                                \     |          |  zzzz = estimated error.
||                                 |    |           \
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* r10o07413.sqa.zmf.tbsite.     5   6   377     1   -432us[ -702us] +/-   63ms
^+ r10o10405.sqa.zmf.tbsite.     5   6   377     2   -678us[ -947us] +/-   63ms

[root@r10o07276.sqa.zmf /home/ahao.mah]
#chronyc sourcestats
210 Number of sources = 2
Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
==============================================================================
r10o07413.sqa.zmf.tbsite.   6   3   325     -0.550      6.451   -232us   161us
r10o10405.sqa.zmf.tbsite.   7   3   387     +0.702     11.702   +235us   541us

[root@r10o07276.sqa.zmf /home/ahao.mah]
#chronyc sourcestats -v
210 Number of sources = 2
                             .- Number of sample points in measurement set.
                            /    .- Number of residual runs with same sign.
                           |    /    .- Length of measurement set (time).
                           |   |    /      .- Est. clock freq error (ppm).
                           |   |   |      /           .- Est. error in freq.
                           |   |   |     |           /         .- Est. offset.
                           |   |   |     |          |          |   On the -.
                           |   |   |     |          |          |   samples. \
                           |   |   |     |          |          |             |
Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
==============================================================================
r10o07413.sqa.zmf.tbsite.   6   3   325     -0.550      6.451   -233us   161us
r10o10405.sqa.zmf.tbsite.   7   3   387     +0.702     11.702   +237us   541us

[root@r10o10405.sqa.zmf /home/ahao.mah]
#chronyc tracking
Reference ID    : 10.210.208.8 (10.210.208.8)
Stratum         : 5
Ref time (UTC)  : Fri Feb 17 09:53:47 2017
System time     : 0.000000227 seconds slow of NTP time
Last offset     : +0.000335872 seconds
RMS offset      : 0.000938629 seconds
Frequency       : 23.669 ppm slow
Residual freq   : +0.560 ppm
Skew            : 10.502 ppm
Root delay      : 0.067548 seconds
Root dispersion : 0.030173 seconds
Update interval : 64.5 seconds
Leap status     : Normal