Intel SRCU31 5.2.9.2RAID Level 0 Example, 5.2.9.3RAID Level 1 Example, Disk #0, Disk #1, Disk #2

RAID Features

Strip size is specified when you create a RAID volume. Strip size options for RAID levels 0, 1, 5, and 10 are specified below.

Table 5-14. Strip Size Availability and RAID Level

			Strip Size
RAID Level
	4K	8K	16K	32K	64K	128K
RAID0	X	X	X	X	X	X
(with < 2 drives RAID 10)
RAID1	X	X	X	X	X	X
RAID5			X	X	X	X

5.2.9.2RAID Level 0 Example

Data on a RAID 0 volume is striped across all of its member disks. The strip size is the amount of logically contiguous data striped on each disk. Since data is spread across several physical disks, accesses tend to be evenly distributed across all the disks. This sharing of the workload increases the throughput when compared to a single physical disk. There is neither parity nor mirroring, so a RAID 0 volume will lose data if one of its member disks fails.

Figure 5-3. Data Map of a RAID Level 0 Volume with 4 Disks, Showing the First 5 Stripes

Disk #0	Disk #1	Disk #2	Disk #3
				Vol 1
D16	D17	D18	D19	Vol 0
D12	D13	D14	D15
D8	D9	D10	D11
D4	D5	D6	D7
D0	D1	D2	D3

Data Map of a RAID Level 0 Volume

Di is the i'th data strip

5.2.9.3RAID Level 1 Example

A RAID 1 volume mirrors the same data on two of its members. This type of array gives good performance and high reliability but its usable capacity is one half of its physical capacity. See Figure 5-4. In a two disk RAID 1 volume, each disk has an identical copy of the data. In the event a disk fails, data integrity is maintained.

Intel® Server RAID Controller U3-1 User’s Manual Rev 1.0 5-15