Overview
| Parameter | RAID 5 | RAID 10 |
|---|---|---|
| Min Disks | 3 | 4 |
| Usable Capacity | (n-1) * size | (n/2) * size |
| Fault Tolerance | 1 drive | Up to 1 drive per mirror pair |
| Write Penalty | 4 | 2 |
| Read Speed | High (n-1) | Very High (n) |
RAID 5 utilizes block-level striping with distributed parity, offering a balance between capacity and redundancy. RAID 10 (1+0) combines mirroring and striping, prioritizing performance and fast rebuild times at the cost of 50% storage overhead.
Performance
Read performance is high for both configurations. However, RAID 5 suffers from a significant write penalty because every write requires reading old data and parity, calculating new parity, and writing both. This results in a Write Penalty of 4. RAID 10 only requires writing the data to two disks simultaneously, resulting in a Write Penalty of 2.
- RAID 5: Best for sequential workloads and read-heavy environments.
- RAID 10: Superior for random write operations and high-transaction databases.
Configuration & complexity
Configuration in Linux environments using mdadm is straightforward:
# Create RAID 5 with 3 devices
mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sda1 /dev/sdb1 /dev/sdc1
# Create RAID 10 with 4 devices
mdadm --create /dev/md0 --level=10 --raid-devices=4 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1RAID 5 rebuilds are resource-intensive. On large SATA drives, the rebuild process can take days, during which the array is vulnerable. RAID 10 rebuilds are much faster as they involve simple data copying from the surviving mirror partner.
When to choose what
Decision criteria based on workload profile:
- RAID 5: General-purpose file servers, backup targets, and cold storage where capacity efficiency is the priority.
- RAID 10: Production databases (ERP, CRM), virtualization hosts, and high-IOPS application servers.
Cost / licensing
RAID 5 is more cost-effective. For a 4-drive setup with 10TB units, RAID 5 provides 30TB of usable space, while RAID 10 provides only 20TB. No specific licensing is required as both are standard features in hardware controllers and software RAID implementations.
Ecosystem & integrations
Both levels are supported by all major hardware vendors (Dell, HPE, Lenovo) and software platforms (Linux mdadm, Windows Storage Spaces, ZFS). In modern high-capacity arrays, RAID 5 is increasingly replaced by RAID 6 or Erasure Coding to mitigate double-disk failure risks.
Verdict
RAID 10 is the go-to for performance-critical applications where disk budget is secondary to uptime and speed. RAID 5 is suitable for cost-sensitive storage of large datasets where write performance is not the primary bottleneck.