During the last 4 days I was busy upgrading my hdds after one of them started to show warnings. I immediately thought it would be easy to swap the HDDs as friends told me that it would be easy. I am just a novice guy with computers.
1.) HDDs - copy the propper way.
Before removing any HDD make sure you can copy your entire drive to another HDD because extracting the date off the old drives can be difficult. The target drive needs to be big enough.
Then install your HDD and copy the data back to your NAS.
What did I do and what does not work?
I swapped the broken drive 4TB drive with a 6TB drive. Then I waited the NAS doing its thing. Then I swapped the other drive and waited again. Once the copying was done the volume partition cannot be increased. The extra storage can only be assigned as spanning. Spanning is to my knowledge just regular space that is not in Raid 1.
I removed all drives from the NAS and connected the drives to the computer via a USB-Sata adapter (Be careful not all work, because you need one that has tyhe power to spin up de drives) and deleted the partitions on both 6TB drives. I wanted to format one of the 6TB drives for windows and the extract the data from the older 4tb drive that I put back into the NAS.
Anyway I made a mistake and put a 6tb and 4tb and the 6tb has overwritten the 4tb and basically lost all data.
I put both 6TB back into the drive to get them configureted as 6TB in Raid 1. Then I bought a software to recover lost Raid partitions. With that software and the 4tb HDD externally attached to the laptop, I could extract the data and copy it directly from the 4TB to the NAS.
The data I copied back onto the drive was without the recycle bin. I never could find the recycle bin of the NAS. I found it when using the extracting raid software. Because I have not found the recycle bin I had about 2TB unwanted files accumulated. A large upgrade was not required but now I cannot return the drives. Money senseless spent on WD.