kubernetes cifs smb flexvolume is missing files
Turns out the problem was caused by using the Apline image as a base for java in a Centos node. Changing the image to a Centos based solved the issue.
We tried this way because we found a hint about same disappearings of files regarding Ubuntu and SMB (with no docker involved) and thought that Apline could be impacted by the same issue being somewhat related more to ubuntu than to RHEL/Centos
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1572132
BTW, the proposed solutions in the thread to use noserverino and 0777 access rights did not solve our issues.