Sometimes the drift file gets off by several hundred seconds and your server will no longer sync
to your ntp reference. With root permissions, you can write the drift file to 0.0 and then stop and
start ntpd.
[root@s83dom0 ~]# cd /
[root@s83dom0 /]# /sbin/service ntpd status
ntpd (pid 2749) is running...
[root@s83dom0 /]# /usr/sbin/ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
*216.152.240.220 164.67.62.194 2 u 33 64 377 60.500 -0.405 10.392
[root@s83dom0 /]# /usr/sbin/ntpq -cas
ind assID status conf reach auth condition last_event cnt
===========================================================
1 33024 9614 yes yes none sys.peer reachable 1
[root@s83dom0 /]# /usr/sbin/ntptime
ntp_gettime() returns code 0 (OK)
time db12ae20.6f3d6000 Mon, Jun 20 2016 13:02:08.434, (.434530),
maximum error 1001160 us, estimated error 672 us
ntp_adjtime() returns code 0 (OK)
modes 0x0 (),
offset -346.000 us, frequency -38.196 ppm, interval 1 s,
maximum error 1001160 us, estimated error 672 us,
status 0x1 (PLL),
time constant 2, precision 1.000 us, tolerance 512 ppm,
[root@s83dom0 /]# /usr/sbin/ntpdate -d -q us.pool.ntp.org
20 Jun 13:03:12 ntpdate[11656]: ntpdate 4.2.2p1@1.1570-o Sat Dec 19 00:56:14 UTC
2009 (1)
Looking for host us.pool.ntp.org and service ntp
host found : natasha.netwurx.net
transmit(209.242.224.97)
receive(209.242.224.97)
transmit(209.242.224.97)
receive(209.242.224.97)
transmit(209.242.224.97)
receive(209.242.224.97)
transmit(209.242.224.97)
transmit(163.44.112.36)
receive(209.242.224.97)
transmit(209.242.224.97)
receive(163.44.112.36)
transmit(163.44.112.36)
receive(163.44.112.36)
transmit(163.44.112.36)
transmit(67.18.187.111)
receive(163.44.112.36)
transmit(163.44.112.36)
receive(67.18.187.111)
transmit(67.18.187.111)
receive(67.18.187.111)
transmit(67.18.187.111)
receive(67.18.187.111)
transmit(67.18.187.111)
receive(163.44.112.36)
transmit(163.44.112.36)
receive(67.18.187.111)
transmit(67.18.187.111)
transmit(108.59.2.24)
receive(108.59.2.24)
transmit(108.59.2.24)
receive(108.59.2.24)
transmit(108.59.2.24)
receive(108.59.2.24)
transmit(108.59.2.24)
receive(108.59.2.24)
transmit(108.59.2.24)
server 209.242.224.97, port 123
stratum 2, precision -23, leap 00, trust 000
refid [209.242.224.97], delay 0.08351, dispersion 0.00038
transmitted 4, in filter 4
reference time: db12a818.14d12844 Mon, Jun 20 2016 12:36:24.081
originate timestamp: db12ae62.b11e578c Mon, Jun 20 2016 13:03:14.691
transmit timestamp: db12ae62.a9ab3aab Mon, Jun 20 2016 13:03:14.662
filter delay: 0.08498 0.08405 0.08351 0.08424
0.00000 0.00000 0.00000 0.00000
filter offset: 0.000358 -0.00007 0.000382 -0.00025
0.000000 0.000000 0.000000 0.000000
delay 0.08351, dispersion 0.00038
offset 0.000382
server 163.44.112.36, port 123
stratum 2, precision -18, leap 00, trust 000
refid [163.44.112.36], delay 0.09645, dispersion 0.00014
transmitted 4, in filter 4
reference time: db12ac2f.34b515d5 Mon, Jun 20 2016 12:53:51.205
originate timestamp: db12ae62.f031769d Mon, Jun 20 2016 13:03:14.938
transmit timestamp: db12ae62.e7178b37 Mon, Jun 20 2016 13:03:14.902
filter delay: 0.09787 0.09645 0.09818 0.09657
0.00000 0.00000 0.00000 0.00000
filter offset: 0.000410 0.000235 0.000033 0.000047
0.000000 0.000000 0.000000 0.000000
delay 0.09645, dispersion 0.00014
offset 0.000235
server 67.18.187.111, port 123
stratum 2, precision -19, leap 00, trust 000
refid [67.18.187.111], delay 0.05397, dispersion 0.00041
transmitted 4, in filter 4
reference time: db12a98c.9d65dc37 Mon, Jun 20 2016 12:42:36.614
originate timestamp: db12ae62.fce2f4bf Mon, Jun 20 2016 13:03:14.987
transmit timestamp: db12ae62.f945b6c3 Mon, Jun 20 2016 13:03:14.973
filter delay: 0.05463 0.05397 0.05489 0.05403
0.00000 0.00000 0.00000 0.00000
filter offset: 0.000826 0.000203 -0.00059 -0.00012
0.000000 0.000000 0.000000 0.000000
delay 0.05397, dispersion 0.00041
offset 0.000203
server 108.59.2.24, port 123
stratum 2, precision -23, leap 00, trust 000
refid [108.59.2.24], delay 0.08600, dispersion 0.00021
transmitted 4, in filter 4
reference time: db12aa78.291ea9ba Mon, Jun 20 2016 12:46:32.160
originate timestamp: db12ae63.5011523d Mon, Jun 20 2016 13:03:15.312
transmit timestamp: db12ae63.457fa5d2 Mon, Jun 20 2016 13:03:15.271
filter delay: 0.08853 0.08665 0.08600 0.08653
0.00000 0.00000 0.00000 0.00000
filter offset: 0.010997 0.010921 0.011108 0.010789
0.000000 0.000000 0.000000 0.000000
delay 0.08600, dispersion 0.00021
offset 0.011108
20 Jun 13:03:15 ntpdate[11656]: adjust time server 67.18.187.111 offset 0.000203
sec
[root@s83dom0 /]# /usr/bin/ntpstat
synchronised to NTP server (216.152.240.220) at stratum 3
time correct to within 15 ms
polling server every 64 s
[root@s83dom0 /]# cat /etc/ntp.conf
# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
# Permit all access over the loopback interface. This could
# be tightened as well, but to do so would effect some of
# the administrative functions.
restrict 127.0.0.1
restrict -6 ::1
# Hosts on local network are less restricted.
#restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool ([URL unfurl="true"]http://www.pool.ntp.org/join.html).[/URL]
#broadcast 192.168.1.255 key 42 # broadcast server
#broadcastclient # broadcast client
#broadcast 224.0.1.1 key 42 # multicast server
#multicastclient 224.0.1.1 # multicast client
#manycastserver 239.255.254.254 # manycast server
#manycastclient 239.255.254.254 key 42 # manycast client
# Undisciplined Local Clock. This is a fake driver intended for backup
# and when no outside source of synchronized time is available.
# Drift file. Put this in a directory which the daemon can write to.
# No symbolic links allowed, either, since the daemon updates the file
# by creating a temporary in the same directory and then rename()'ing
# it to the file.
driftfile /var/lib/ntp/drift
# Key file containing the keys and key identifiers used when operating
# with symmetric key cryptography.
keys /etc/ntp/keys
# Specify the key identifiers which are trusted.
#trustedkey 4 8 42
# Specify the key identifier to use with the ntpdc utility.
#requestkey 8
# Specify the key identifier to use with the ntpq utility.
#controlkey 8
server us.pool.ntp.org
[root@s83dom0 /]# cat /var/lib/ntp/drift
-38.072