I recently added two more 4 terabyte Western Digital hard drives to Betelgeuse and reformatted the entire server as a redundant array of independent disks (RAID) 10. This technology requires a minimum of four drives. It automatically mirrors a pair of drives together and then stripes the pair to two more hard drives. This consumes 50% of the overall disk space for the sake of mirroring/redundancy, but with a RAID-10 set up, I could theoretically lose two hard drives (one from each mirrored set) and still have all of my data.
For anyone interested in creating their own RAID server, just be mindful that no matter how much striping/mirroring you have on a single device, it’s still not a substitute for having a physically separate backup. I still backup my essential documents to a secure, cloud server “just in case.”