RAID Types

QNAP NAS devices support several RAID types. Each type provides a different combination of striping and redundancy.

Important:

RAID Type

Count

Disk Failure Tolerance

Capacity

Overview

Single

1

0

Size of the one disk

  • A single disk is used for storage.

  • It does not provide any disk failure protection and performance benefits.

  • It should be selected if only one disk is available and if a data backup plan is in place.

JBOD (just a bunch of disks)

1 or more

0

Combined disk capacity

  • JBOD appends disks together in a linear fashion. QTS writes data to a disk until it is full, and then writes to the next disk.

  • JBOD allows all of the disks capacity to be used.

  • JBOD Single is not real RAID. It does not provide any disk failure protection or performance benefits.

  • JBOD is generally not recommended. RAID 0 should be used instead.

RAID 0

2 or more

0

Combined disk capacity

  • Disks are combined together using striping.

  • RAID 0 offers the fastest read/write speeds and allows all disk capacity to be used

  • No disk failure protection. This type should be paired with a data backup plan.

RAID 1

2

1

Disk size divided by 2

  • An identical copy of data is stored on two disks.

  • If either disk fails, data can still be read from the other disk.

  • Half of the total disk capacity is lost, in return for a high level of data protection.

  • Recommended for NAS devices with two disks.

RAID 5

3 or more

1

Total number of disks minus 1 disk

  • Data and parity information are striped across all disks.

  • The capacity of one disk is lost for parity. This means that if any one disk fails, it can be replaced and the data on it can be restored.

  • Striping means read speeds are increased with each additional disk.

  • Recommended for a good balance between data protection and speed.

RAID 6

4 or more

2

Total number of disks minus 2 disks

  • Data and parity information are striped across all disks.

  • Same as RAID 5, but two disks are used for parity. This means that it protects against two disk failures, but the capacity of two disks are lost.

  • Recommended for business and general storage use. It provides high disk failure protection and read performance.

RAID 10

4 or more (even number required)

1 per pair of disks

Total number of disks divided by 2

  • Every two disks are paired using RAID 1 for failure protection. Then all pairs are striped together using RAID 0.

  • Excellent read/write speeds and high failure protection, but half the disk capacity is lost.

  • Recommended for application or database storage.

RAID 50

6 or more

1 per disk sub-group

Total number of disks minus 1 disk per sub-group

  • Multiple small RAID 5 groups are striped to form one RAID 50 group.

  • Better failure protection and faster rebuild times than RAID 5. More storage capacity than RAID 10.

  • Better random access performance than RAID 5 if all of the disks are SSDs.
  • Recommended for enterprise backup with ten or more disks.

RAID 60

8 or more

2 per disk sub-group

Total number of disks minus 2 disks per sub-group

  • Multiple small RAID 6 groups are striped to form one RAID 60 group.

  • Better failure protection and faster rebuild time than RAID 6. More storage capacity than RAID 10.

  • Better random access performance than RAID 6 if all of the disks are SSDs.
  • Recommended for business storage and online video editing with twelve or more disks.