What Is RAID 10 : How It Works, Pros, Cons, & When to Use

Summary

RAID 10 is a hybrid configuration that "stripes" data across "mirrored" pairs of disks, combining the performance of RAID 0 with the redundancy of RAID 1.
RAID 10 excels in write-intensive tasks like databases because it has no "write penalty" from parity calculations, unlike RAID 5.
RAID 10 can survive multiple disk failures—as long as no two failed disks are from the same mirrored pair.
The main drawback of RAID 10 is a 50% capacity overhead, meaning half of your total disk space is used for redundancy, making it costly.
RAID 10 is ideal for mission-critical databases, high-traffic applications, and virtualization environments where both performance and uptime are non-negotiable.

In our introduction to RAID, we explained how RAID, or a Redundant Array of Independent Disks, came into being as a foundational technology. In their presentation at the 1988 SIGMOD Conference, Patterson, Gibson, and Katz demonstrated how it was possible to combine multiple drives to improve storage performance, provide fault tolerance, or both. They called this configuration RAID.

RAID can be configured in many ways, and each configuration (such as RAID 0, 1, and 5) offers a unique balance of the storage goals we mentioned above.

That’s another way to say that each RAID configuration presents a trade-off (explained in more detail in our guides on RAID 0 and RAID 1).

You could have the incredible performance of RAID 0, but a single drive failure meant losing everything.
Or, you could have the iron-clad redundancy of RAID 1, but at the cost of 50% of your capacity and no speed boost.

This dilemma first led to parity-based solutions like RAID 5 and RAID 6. This configuration offered a compromise but came with write performance penalties (which we have explained in detail in our RAID 5 and RAID 6 guides).

To achieve the best of both worlds without compromise, engineers then developed "Nested RAID."

What Is a Nested RAID?

Think of a nested RAID as a hybrid approach that combines the best features of different RAID levels. The most used of these hybrids is RAID 1+0 (more commonly called RAID 10).

So, What Is RAID 10?

It’s a "stripe of mirrors": data is first mirrored onto pairs of disks for safety (the RAID 1 function), and then data is striped across these mirrored pairs for performance (the RAID 0 function). This elegant solution provides both high speed and strong fault tolerance. This design directly overcomes the limitations of its predecessors.

How RAID 10 Works: Design & Mechanics of “Mirrored Stripes”

The working of RAID 10 can be understood in two simple steps.

First, drives are paired into small RAID 1 mirrors. This “mirroring” means that each pair holds identical copies of every block, so if one disk dies, its twin still serves data.

Second, those mirrored pairs are joined with RAID 0 striping: blocks are spread evenly across each mirror set so that multiple disks can work in parallel.

For example, with four disks, you create two RAID 1 pairs, then stripe data across those pairs. This mirrored-stripe RAID 10 layout delivers both throughput and redundancy in one array.

In this way, RAID 10 architecture combines the speed of striping with the security of mirroring.

This design makes RAID 10 a great alternative for applications that require high availability.

If any single drive fails, its mirrored partner can immediately take over. This ensures zero downtime.

A RAID 10 array can even survive multiple drive failures (as long as no two failed drives are from the same mirrored pair).

Key Features & Performance Profile for RAID 10

Metric	RAID 10	Notes
Sequential Read	≈ N × (single-disk bandwidth)	Striped across N/2 mirror pairs; scales until controller/bus limits
Sequential Write	≈ (N/2) × (single-disk bandwidth)	Each stripe writes to two disks in parallel; no parity-penalty
Random Read IOPS	≈ 2 × (single-disk IOPS) per mirror pair	Reads can be distributed to either disk in each mirror, doubling IOPS per pair
Random Write IOPS	≈ (N/2) × (single-disk IOPS)	Each write is duplicated, but parallel striping across pairs boosts overall throughput
Capacity Efficiency	50% usable space	Mirrors halve raw capacity; no extra parity disks
Scalability	+2 disks ⇒ +1 × capacity + performance boost	Add mirror pairs to grow both capacity and I/O; no parity calculation means no increase in rebuild time

Comparison Between RAID 10, RAID 0, RAID 1, & RAID 5

RAID Level	Fault-Tolerance	Random Performance	Sequential Performance	Capacity Utilization
0	★☆☆☆ (any drive fails → data lost)	★★★★☆	★★★★☆	100%
1	★★★★☆ (one drive per mirror)	★★★☆☆	★★☆☆☆	50%
5	★★★☆☆ (one drive)	★★★☆☆	★★★★☆	≈ (N – 1) / N (≈ 75% for 4 drives)
10	★★★★★ (one per mirror pair; multiple across pairs)	★★★★☆	★★★★☆	50%

Note: RAID 5 is important in the context of RAID 10, as essentially, it’s a configuration that attempts to achieve the same storage performance goals as RAID 10.

RAID 10 vs RAID 5

The key difference between RAID 5 and RAID 10 is how they achieve redundancy.

RAID 10 uses mirroring, which offers excellent random write performance and fast rebuilds since data is simply copied from the surviving mirror.
RAID 5 uses parity calculations, which saves on capacity but introduces a write penalty and slower, more complex rebuilds.

This makes RAID 10 a superior choice for performance-critical applications like online databases and highly demanding virtualization servers.

Key Features & Advantages of RAID 10

Earlier, we explained how RAID 10 works by combining two proven techniques (mirroring and striping) to deliver both speed and safety.

First, data is duplicated in pairs (RAID 1); then, these mirrored pairs are striped (RAID 0).

This “striped mirrors” design gives you the following advantages.

High throughput for small, random I/O: Write requests go to two disks in parallel without the costly read-modify-write cycles of parity-based RAID configurations. So, one of the most desirable RAID 10 benefits is its near-linear write performance.
Accelerated reads: Each mirrored pair can service read requests independently, which can potentially double random-read IOPS compared to a single drive.
Exceptional fault tolerance: You can lose one drive per mirror without downtime, and even multiple drives if they’re in different pairs.
Fast, simple rebuilds: When a disk fails, only its twin is re-mirrored. This avoids the long, I/O-heavy parity calculations of RAID 5 or 6. The rest of the array stays fully operational.
Scalability: You can add more mirror sets and stripe across them without introducing parity overhead.

These core strengths make RAID 10 advantages and disadvantages heavily skewed toward environments where performance and availability are mission-critical.

Limitations of RAID 10

RAID 10 limitations stem primarily from capacity and cost considerations.

50% storage overhead: In RAID 10, every bit is written twice, so you need double the raw disk capacity for a given usable volume. In comparison, RAID 5 can reduce overheads to below 10% in large configurations (10+ disks).
Write I/O load: Every write command in a RAID 10 setup generates two physical writes (one per mirror). This is essential for redundancy but places more demand on controllers and backplanes compared to a single disk or RAID 0.
Overkill for small workloads: For very small databases or non-mission-critical apps, the “50% capacity penalty” of RAID 10 overshadows the benefits of extreme resilience. Overall, in such applications, RAID 10 becomes unjustifiable.

On the whole, the chief trade-off with RAID 10 is paying for steadfast performance and uptime with twice the number of disks.

When to Use RAID 10: Ideal Deployment Scenarios

RAID 10 offers a unique profile of high performance and high cost. Because of this, there are very specific RAID 10 use cases where it is the undisputed best choice.

Ideal deployments include the following.

High-Transaction Databases: Applications like online transaction processing (OLTP), financial trading platforms, and busy e-commerce sites that handle thousands of small, random read/write operations per second benefit a lot from RAID 10's low latency and the absence of a write penalty.
Business-Critical Enterprise Applications: Core systems like ERP and CRM software, which are vital to a company's daily operations, are placed on RAID 10 to ensure maximum performance and availability.
Virtualization Environments: Servers hosting dozens or hundreds of virtual machines (VMs) generate highly variable and demanding I/O patterns. RAID 10 can handle this mixed workload smoothly and can ensure a responsive experience for all VMs. In these scenarios, the cost is easily justified by the need for constant, reliable performance.

RAID 10 Failure: Common Causes

Of course, RAID 10 is highly resilient, but it's not immune to failure. Storage system admins must understand the potential RAID 10 failure causes.

The most significant risk in a standard RAID 10 (a stripe of mirrors) is the loss of a complete mirrored pair.

The array can easily survive one drive failing and can even handle multiple failures, but only if each failed drive belongs to a different mirrored pair.

The moment both drives in the same pair fail simultaneously, that segment of the stripe is lost, and the entire array goes offline. This is the most common cause of a catastrophic hardware-related RAID 10 failure.

Beyond a failed disk, common RAID 10 failure causes include the following.

Controller breakage: If the RAID card itself malfunctions, healthy drives suddenly become unreadable.
Human mistakes: One wrong command—deleting the wrong system folder, reformatting a volume by accident, or misconfiguring the array—can wipe out critical data in seconds.
External shocks: Power spikes, malware, or filesystem corruption can all leave your disks intact but your data inaccessible.

When these scenarios overwhelm simple rebuilds—especially if an entire mirror pair or the controller firmware fails—you need specialized RAID 10 data recovery.

RAID 10 Data Recovery

When a RAID 10 failure occurs due to the loss of both drives in a mirrored pair or controller malfunction, a simple rebuild is impossible. This is when you need to contact professional RAID 10 data recovery service to get back your critical data.

RAID 10 Recovery Process at Stellar Data Recovery

Our engineers have a deep understanding of how RAID 10 and other RAID levels work. We have dealt with RAID 10 failure cases wherein the original configuration data is lost. Even then, our experts can manually piece together your mirrored pairs and stripes. This allows them to recover your complete datasets when others can’t.
We have a library of powerful, specialized software tools that we use to create safe copies of your drives. Once this is done, we reconstruct your array in a secure, dust-free Class 100 cleanroom. This ensures there's no risk of further damage while we work to preserve every last bit of your data.
In the last 3 decades, our data recovery experts have conducted thousands of successful RAID recoveries. This vast experience means our team can quickly figure out what went wrong and apply the safest RAID recovery strategy to get your data back.

We hope this guide has been able to explain how RAID 10’s mirrored-stripe design delivers unparalleled speed and uptime. This is ideal in applications where every I/O and every second of availability counts.

Evaluate your requirements to see if RAID 10 fits your mission-critical workloads.