I promised to come back to the 2nd part of my post. After the checking of the consitency was done I expected to do 1 more step, expanding the drive to it’s full capacity. So when I woke up this morning, the first thing I did was checking my precious disks.
Big was my surprise that the Synology DSM software already decided to use the full capacity of the disks. So, tadaa.. Fully mirror RAID 1 and 4TB (3,6TB effective) for my movies and stuff. I love it.