I have a DS220+ with 2 identical drives, configured as RAID, so just one volume. Everything was working great, but to access the new object-recognition in photos, I added RAM, which caused some corruption and now the volume is read-only and won’t repair itself (even after removing the RAM). So now I’m preparing to do an external backup and rebuild the NAS. But now I’m wondering: If volume issues are more likely than drive issues, should I forget about RAID, create one volume on each drive, and use the second volume as a local backup? Or is RAID still the best first line of defence? (Or is there a way I can do both with two drives?
RAID10 does not offer more ‘protection’ than RAID1 as it is just half of the disks of an even number of disks bun hed up as one and mirrored onto the other half. the capacuty of a 2 disk 4TB RAID1 is the same as a 4 disk 2TB RAID10. using 8 disk of 8TB in a RAID10 would give a usa le capacity of 32TB, using RAID5 it would be 56TB(!), even RAID6 would have more capacity (48TB) and you could lose up to two disks at a time. here is a calculator for thisi just saw you other response where you basically explained the same. sorry!