During planning my RAID setup on a Synology Disk Station I've done a lot of reading about various RAID types, being this a great reading: RAID levels and the importance of URE (Unrecoverable Read Error).
However, one thing remains unclear to me:
Let's have two scenarios:
- An array is a RAID 1 of 2 drives
- An array is a RAID 5 of 3 drives
The same assumptions for both scenarios:
- Let's have 100.000 files on the RAID array
- One drive fails (needs replacement)
- There happens to be one bad sector (URE) during rebuilding the array
What happens? Does the RAID rebuild with 99.999 files doing fine and 1 file lost? Or am I going to lose all 100.000 files?
If the answer requires the knowledge of the filesystem type, let assume it's BTRFS or ZFS being the filesystem.