Thank you for your post.
I am unable to reproduce this behavior with FileMaker Server 13v10 on Windows Server 2012 R2 (Standard) after enabling progressive backups, allowing it to run, and then changing the System Time back an hour. I would recommend updating to FileMaker Server 13v10. You may also check that no Anti-Virus or Security software is running on the Directory/Path of your Progressive Backups.
I hope this information is of use!
How often are the progressive backups scheduled?
They are done every 60 minutes.
I think that might be the issue and would only happen when the time is set back. It may be the folder has the exact same name and that throws it off. It would make sense.
TSPigeon did you test this with the backups set at 60 minutes? You may want to test by setting the system time to before the automatic time change in the OS and see if that makes a difference. Might be a difference in auto or manual setting of the time.
You may want to try setting the progressive backup to 30 minutes or less if you can. They are generally very fast. I usually use 20 minutes for progressive and have regular backup on the hour.
Thank you for the response.
I will take this information into account and test with it further. Thank you.