[ntp:questions] ntpd step recovery time

Nickolay Orekhov nowhere at mail.ru
Mon Apr 23 07:12:15 UTC 2012


Hello, All!

I've got the following configuration:

#
# cat /etc/ntp.conf
# drift frequency file
driftfile  /fs/sd/etc/ntp.drift

# midist  : increased minimal distance for PPS reference clocks ( default
0.001s )
tos mindist 0.032

# panic   : zero to accept initial big shifts ( default 1000s )
# stepout : how many seconds wait before stepping to spike ( default 900s )
# step    : step threshold in seconds ( default 0.128s )
tinker panic 0 stepout 60

# disable authentification for broadcast network
disable auth

server 10.1.1.252 prefer iburst maxpoll 3
broadcastclient

The following sequence of actions performed:

1. The server becomes synchronized
2. Someone wants to measure how much time it will take for ntpd to make a
STEP. Using "date" command he changes system time significantly.
3. According to "tinker stepout 60" we assume that after 60 seconds of
spike_detect STEP will be performed.

But in reality step will be performed about 5 minutes to perform. Why it
takes so long?
Can we guarantee maximum stepout time somehow?

Regards, Nick


More information about the questions mailing list