Step Up to Five Bays Without Overpaying

When you actually need a fifth bay

Most homes are well served by four bays, so a 5-bay is for people who have outgrown that or who want a specific safety margin. The extra bay does one of two things. It can simply add usable capacity, giving you a larger pool for a big Plex library or a growing archive. Or it can buy resilience: with five drives you can run RAID6 or Synology's SHR-2, which keeps your data safe even if two drives fail at the same time.

That second-drive-failure protection matters more than people expect during a rebuild. When one large drive fails and the array is rebuilding, the remaining drives are under heavy load, and a second failure in that window would be catastrophic on a single-parity setup. SHR-2 or RAID6 covers exactly that risk, which is why larger arrays and business deployments lean towards it.

If you mainly want more space and are comfortable with single-drive protection, a 5-bay running SHR or RAID5 simply gives you more usable terabytes than a 4-bay. The choice between extra capacity and extra redundancy is yours to make.

Best 5-bay NAS by need

How much to budget

Budget the appliance and five drives as one purchase, and be realistic: at five bays the drives almost always cost more than the enclosure, particularly at the high capacities that justify a 5-bay in the first place. The box price is just the starting point.

Use NAS-rated CMR drives such as Seagate IronWolf, WD Red Plus or Toshiba N300, and for the lowest price per terabyte at large capacities Seagate Exos enterprise drives are the sensible choice. For heavier business duty cycles, enterprise drives like Exos or Ultrastar are built for it. Avoid SMR drives in any RAID array.

Decide your RAID layout before buying, because it changes how much usable space you get. SHR-2 or RAID6 uses two drives' worth of capacity for protection, so five drives give you the usable space of about three. Single-parity SHR or RAID5 uses one drive, leaving about four drives usable. That difference is the price you pay for surviving a second failure.

Single or dual-drive redundancy on five bays