Just brought up Oracle 12.2 DB on Windows VM.
I have set RMAN backup to run nightly at 10:00pm.
In the alert.log, I noticed ALTER TABLESPACE ... BEGIN BACKUP for each and every tablespaces running at 4 hours interval. Today was at 2:30am and 6:30am; yesterday was at 02:30, 06:30, 10:30, 14:30, 18:30 and 22:30.
What's causing this? Could it be the VM? I have search the docs and I am not doing any copying; nor any batch file is executing the copy.