RAID-TEC (Triple Erasure Coding) is a type of RAID array with triple parity developed by NetApp for data storage systems. This technology is used to increase the fault tolerance of disk arrays and protect data in enterprise storage environments.
In RAID-TEC, data is distributed across multiple disks while additional parity blocks are created. This allows the system to continue operating even if several drives fail simultaneously. Such a level of protection is especially important for large storage systems and data centers.
RAID-TEC technology is used in NetApp enterprise storage systems (for example, in systems running ONTAP software) and is designed to operate with arrays consisting of a large number of high-capacity disks.
How RAID-TEC works
RAID-TEC uses a mechanism called Triple Erasure Coding, which means that three different parity blocks are created in the array to help restore data in case of disk failures.
The system uses three types of parity:
- Row Parity — horizontal parity
- Diagonal Parity (DP) — diagonal parity
- Anti-Diagonal Parity (AP) — reverse diagonal parity
This approach provides a higher level of protection compared to other RAID types.
Key features of RAID-TEC
RAID-TEC has several important characteristics:
- Triple parity — the array can tolerate the failure of up to three disks simultaneously.
- High resilience during rebuild operations, when the risk of additional disk failures increases.
- Designed for large-capacity arrays using high-capacity HDDs.
- Optimal RAID group size — typically 20–29 disks.
Compared with RAID-DP (double parity), this architecture significantly reduces the risk of data loss, especially when using modern drives with capacities of 6–10 TB or more.
Where RAID-TEC is used
RAID-TEC is used in enterprise storage systems where high fault tolerance is critical.
Typical use cases include:
- storage systems in data centers
- cloud provider infrastructure
- archival and backup storage systems
- backup and disaster recovery systems
- corporate data processing platforms
For example, in a data center infrastructure, RAID-TEC can be used to store backup copies or archival data. Thanks to triple parity, the system can preserve data even if multiple disks fail.
RAID-TEC and other RAID levels
RAID-TEC is an evolution of parity-based RAID technologies.
Comparison:
- RAID 5 — single parity disk
- RAID 6 — two parity disks
- RAID-DP — double parity (NetApp technology)
- RAID-TEC — triple parity
Adding a third level of parity makes RAID-TEC particularly effective for arrays with a large number of drives, where the probability of simultaneous disk failures is higher.
Thus, RAID-TEC is a high-reliability data storage technology designed for large storage systems and data centers where data protection is critical.