RAID Types

Important:

RAID Type

Number of Disks

Disk Failure Tolerance

Overview

RAID 0

≥ 1

0

  • Disks are combined together using striping.

  • RAID 0 offers the fastest read and write speeds, and uses the total capacity of all the disks.

  • Provides no disk failure protection. This RAID type must be paired with a data backup plan.

RAID 1

2

1

  • An identical copy of data is stored on each disk.

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

  • Recommended for storing important data.

RAID 5

3–9

1

  • Data and parity information are striped across all disks.

  • The capacity of one disk is lost to store parity information.

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

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

  • Ideal for running databases and other transaction-based applications.

RAID 6

5–10

2

  • Data and parity information are striped across all disks.

  • The capacity of two disks are lost to store parity information.

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

RAID 10

4

1 per pair of disks

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

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

  • Recommended for applications that require high random access performance and fault tolerance, such as databases.

RAID 50

3–9 per subgroup

1 per disk subgroup

  • 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.

  • Recommended for applications that require high fault tolerance, capacity, and random access performance.

RAID 60

5–10 per subgroup

2 per disk subgroup

  • 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.

  • Recommended if you need higher fault tolerance than RAID 50.

Triple Mirror

3

2

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

  • There is also no degradation in performance while the RAID group is being rebuilt.

  • Read performance is increased, but capacity is greatly decreased.

  • Triple Mirror is suitable for storing critical data.

RAID-TP

8–11

3

  • Data and parity information are striped across all disks.

  • The capacity of three disks are lost to store parity information.

  • RAID-TP adds an extra level of redundancy over RAID 6.