RAIDar can see Duo 1 but cannot access it

Thanks StephenB.
I used the linux reader to backup the data of disk 1. It took me about a week to complete because there were some files that cannot be recovered by linux reader. The backup process was being halt when there was a file not being able to be recovered. Popup box appeared and waited for my response everytime. Finally, I can recover about 450G data, slightly less than original total data size.
After that, I tried the OS reinstallation to my RN Duo. It worked fine. The file structure was reconstructed. Some of the files that cannot be recovered by linux reader become available. However, the data in the harddisk is found more than before I had the problem in the RN Duo. I had about 630G before the problem but I have nearly double the data, 1.1T, after the OS installation. Appreciated if you can advise how can I found the difference in the data and remove these files.
I'm using X-Raid in my RN Duo. Thanks again in advance.