Do not understand how WD Backup works, need help

I have a 8TB WB My Book. I am using the WD Backup Software.

First off, IF I specified everything on my HD to be backed up, the max space it would take up is 1.7TB. However, my My Book shows that 6.7TB is used. Does WD Backup keep multiple copies of files? Does it automatically delete older copies? I cannot figure how all the space is being taken up. I assume it would only backup new files. The lack of configurability and visibility is annoying!

Second, WD Backup reports two things. 1) I get “Some file failed to backup” Clicking to View button just takes me to the WB Backup screen and provides no additional information. 2) The WD Backup often tells me it missed a backup. Why did it miss the backup? I know specifically today, the machine was on and idle when the backup was missed.

I checked the documentation and except for telling you the basics, it is pretty much useless. Is there any docs that would give me more information? I pretty much ready to give up on the software unless I can get more info as to what it is doing. I had Memeo Backup and stopped using it when I purchase PC and the MyBook Drive. Now I am regretting what is going on because there is no visibility.

Hoping someone can help me with more information.

Hello TurboPascal,

WD Backup does an incremental backup. It backs up the updated or modified files after completing the first backup. Did you check the backed up files manually from My Book? If not, then recommending to refer this article to check the backed up files manually and for more details: