QTS supports several RAID types. Each type provides a different combination of performance and redundancy.
If disks with different capacities are combined in one RAID group, all disks function according to the capacity of the smallest disk. For example, if a RAID group contains five 2 TB disks and one 1 TB disk, QTS detects six 1 TB disks.
QNAP recommends the following when mixing disks of different capacities.
Create a separate RAID group for each capacity.
Combine the RAID groups using storage pools.
If different types of disk (HDD, SSD, SAS) are combined in one RAID group, the RAID group will function according to the speed of the slowest disk.
RAID Type |
Number of Disks |
Disk Failure Tolerance |
Capacity |
Overview |
---|---|---|---|---|
Single |
1 |
0 |
Total disk capacity |
|
JBOD (just a bunch of disks) |
≥ 2 |
0 |
Total combined disk capacity |
|
RAID 0 |
≥ 2 |
0 |
Total combined disk capacity |
|
RAID 1 |
2 |
1 |
Half of the total combined disk capacity |
|
RAID 5 |
≥ 3 |
1 |
Total combined disk capacity minus 1 disk |
|
RAID 6 |
≥ 4 |
2 |
Total combined disk capacity minus 2 disks |
|
RAID 10 |
≥ 4 (Must be an even number) |
1 per pair of disks |
Half of the total combined disk capacity |
|
RAID 50 |
≥ 6 |
1 per disk subgroup |
Total combined disk capacity minus 1 disk per subgroup |
|
RAID 60 |
≥ 8 |
2 per disk subgroup |
Total combined disk capacity minus 2 disks per subgroup |
|