well, so I found reason of my problem by myself :) all is about CRON job, last line from /etc/crontab */2 * * * * root /bin/bash /usr/bin/sync_ntp_rtc.sh - that mean that this scrip will run every 2 minutes solution: I have changed this line to run every 24 hours * */24 * * * ..... or it is possible...

Hello I'm running NAS OpenMediaVault on Nano Pi NEO2 (Debian Jessie) Kernel 4.11.2. I have set up notification from my NAS which is good, but when I allowed to NTP time synchronization I'm bombarded on e-mail every 2 minutes information: Connecting to NTP server log: /var/log/sync_ntp_rtc.log where ...