RAID 10
What RAID 10 means
RAID 10, also written as RAID 1+0, combines two techniques:
- Mirroring, associated with RAID 1, keeps duplicate copies of data on separate drives.
- Striping, associated with RAID 0, spreads data across multiple mirrored pairs.
On a compatible NAS, this arrangement can keep data available when a drive fails while allowing storage operations to use multiple drives. RAID 10 commonly requires at least four drives, but the exact requirements and implementation depend on the NAS.
Why it matters on a NAS
RAID 10 is relevant when a buyer wants redundancy without using parity-based RAID. Because data is mirrored, a failed drive can often be replaced while the NAS rebuilds the affected mirror.
The trade-off is capacity. RAID 10 generally provides about half of the combined raw drive capacity for usable storage, before any filesystem or system overhead. Its fault tolerance also depends on which drives fail: multiple failures may be tolerated if they occur in different mirrored pairs, but failures within the same pair can put data at risk.
RAID 10 is not a backup. It does not protect against accidental deletion, malware, theft, fire, or other events that affect the NAS and its copies at the same time.
When the label is useful—and what it leaves unknown
RAID 10 can matter for a NAS used for workloads where redundancy and consistent storage access are priorities. It may be less relevant when the product has too few drive bays, when maximum usable capacity is more important, or when an independent backup provides the main recovery plan.
A product page that lists “RAID 10” only indicates that the NAS identifies this mode as supported. It does not, by itself, rate the NAS's speed, rebuild behavior, reliability, included drives, controller quality, or overall data protection. It also does not confirm that every drive combination is supported.
What to check on a product page
Look for:
- The number of drive bays and whether RAID 10 requires a particular bay count
- The supported RAID modes and whether RAID 10 is available with the intended drive type
- Whether drives are included or must be supplied separately
- Any stated capacity limits, drive compatibility requirements, or expansion restrictions
- How the product describes drive replacement, rebuilds, and storage alerts
- Backup features or recommended backup methods, since RAID 10 is not a backup
If these details are missing, the RAID 10 capability may be known while the product's usable capacity, supported drive combinations, and rebuild behavior remain unknown.
Nearby concepts include RAID 0, RAID 1, RAID 5, and RAID 6. These modes use different combinations of striping, mirroring, or parity and therefore make different capacity and fault-tolerance trade-offs.