RAID 10 definition
RAID 10 is a nested (hybrid) Redundant Array of Independent Disks (RAID) configuration that combines RAID 1 (mirroring) and RAID 0 (striping). It provides both data redundancy and improved performance by striping data across multiple mirrored sets of drives. RAID 10 is often written as “RAID 1+0” to distinguish it from the standard levels of RAID.
How RAID 10 works
RAID 10 starts with RAID 1, where data is mirrored across pairs of drives to achieve redundancy. Because of mirroring, the number of drives in a RAID 10 configuration must be even (and in any event no less than four).
After the mirroring, RAID 0 striping is applied. The mirrored pairs are striped together (i.e. the data is distributed across these pairs in a striped fashion) to enhance performance. Striping allows simultaneous read and write operations across multiple drives.
Advantages of RAID 10
- Fault tolerance. If one drive in a mirrored pair fails, the system can continue to operate without interruption using the mirrored drive.
- Higher performance. RAID 10 is particularly suited to read-intensive and write-intensive workloads due to its striping component.
- Recovery. In the event of a drive failure, the RAID array can be rebuilt by copying data from the surviving drive in the mirrored pair to a replacement drive.