Complex sentence: One drive from each of the RAID 5 sets could fail without loss of data; for example, a RAID 50 configuration including three RAID 5 sets can only tolerate three maximum potential drive failures.
Split into simpler sentences: One drive from each of the RAID 5 sets could fail without loss of data. For example, a RAID 50 configuration including three RAID 5 sets can only tolerate three maximum potential drive failures.