[Samba] Avoiding constant HDD access

[Albert Berger]

I'm running a Samba server on Raspbian and observing that Samba during idle 
periods is constantly (every minute) writing to HDD (maybe doing some 
journaling?) what causes the HDD to constantly spin and never standby:

root at rpi:~# pidstat -dl 20
Linux 4.4.50-v7+ (localhost) 	11/07/2018 	_armv7l_	(4 CPU)
    
04:10:08 AM   UID  PID   kB_rd/s   kB_wr/s kB_ccwr/s iodelay  Command
04:10:28 AM     0  832      0.00      0.20      0.20       0  /usr/sbin/smbd -D
    
04:11:08 AM   UID  PID   kB_rd/s   kB_wr/s kB_ccwr/s iodelay  Command
04:11:28 AM     0  832      0.00      0.20      0.20       0  /usr/sbin/smbd -D
    
04:12:08 AM   UID  PID   kB_rd/s   kB_wr/s kB_ccwr/s iodelay  Command
04:12:28 AM     0  832      0.00      0.20      0.20       0  /usr/sbin/smbd -D

Is there some way (via configuration setting or maybe recompiling with some 
parameter) to turn off this constant disk io?

/Al