What I try to say is, if I install lastest version available now, I'll want update to 6.2.
Now I have a DS-413J with 4 4TB hard drives (12TB SHR) and no space free. I transfered a few TB to external disks to continue using my Synology.
Because this, I decided build a huge Xpenology Bare Metal, with 40tb for now, and sell DS-413J.
What I understood, one possible problem with the update would be only with the system itself, so, I could leave data intact just by disconnecting my raid disks and connecting a spare disk to test, right?