We have samba 4.10.6-1 running on AIX 7.2 TL05sp4 in our environment . No changes were done at AIX server end in recent times but few of the end users are facing a unusual issue of copying files to samba shares on aix lpars. When end user tries to copy and paste a file from laptop to samba share, For some reason it assumes the files already exists on the Samba share (which they do not) because we are asked if we want to overwrite the existing files , if we accept; the file is written by the same name but they are empty and then an access denied message pops up. But when we try to first copy(scp) the files to any other aix lpar /iSeries lpar on the network and then to the Samba share on destination AIX it works . We also tried to do an ftp/winscp to the Samba share from the laptop and it worked. Incase anyone faced a similar issue ,please suggest if there is any resolution/workaround for it.
Looking into the Samba logs ( generated with log level = 10) is the best option to troubleshoot these kind of issues.