RAID 10 (Disk Mirroring and Striping)

RAID 10 incorporates the technique of striping (RAID 0) across multiple disk mirrors (RAID 1). At least four physical disks are required to create a RAID 10 virtual disk/array, as shown in Figure 1.

Table 1 describes RAID 10 across a number of parameters.

Table 1  RAID 10

Parameter

Rating

Description

Read Performance

RAID 10 provides read performance comparable to RAID 0 (striping).

Write Performance

RAID 10 provides write performance comparable to RAID 1 (disk mirroring). Write performance is comparatively lower than read performance because data (original and mirror) is written on two physical disks simultaneously.

Fault Tolerance

RAID 10 virtual disks/arrays can tolerate the failure of one physical disk in each RAID 1 set. The failed disk must be replaced to ensure continued fault tolerance. Otherwise, the single working physical disk in the partially degraded RAID 1 set becomes the single point of failure for the entire RAID 10 virtual disk/array.

Efficient use of disk capacity

Like RAID 1, RAID 10 uses the mirroring technique for redundancy, thereby using 50% of the combined disk capacity for mirroring data. For example, four 100 GB physical disks (a total of 400 GB) create a 200 GB virtual disk/array because the remaining 200 GB is used to store mirror data.

Note: When creating a RAID 10 virtual disk/array with physical disks of different sizes, the storage space added to the array by each physical disk is limited to the size of the smallest physical disk. This is true for any RAID virtual disk/array using the disk mirroring technique. For example, a RAID 10 virtual disk/array comprising of 150 GB, 200 GB, 100 GB, and 80 GB physical disks is sized at 320 GB (four times the size of the smallest physical disk 80 GB).

Automatic rebuild

Available.

Minimum number of drives

 

4 

 

Figure 1 describes RAID 10.

Figure 1  RAID 10: Illustration

Note: An Adobe Flash® demonstration of RAID 10 is not provided. RAID 10 incorporates the technique of striping (RAID 0) across multiple disk mirrors (RAID 1) arrays. View demonstrations for RAID 0 and RAID 1 for an understanding of how RAID 10 arrays are built.