RAID 50 Example

LSI 2108/2208 SAS MegaRAID Configuration Utility User's Manual

RAID 50

RAID 50 is a combination of RAID 5 and RAID 0. This type of drive group is called a spanned drive group because data is striped across multiple RAID 5 drive groups. RAID 50 requires at least 6 drives. The following illustration provides a visual ex- ample of a RAID 50 virtual drive group.

RAID 50

RAID 0

		RAID 5			RAID 5
Drive A		Drive B	Drive C	Drive D	Drive E	Drive F
Segment 1		Segment 2	Parity (1,2)	Segment 3	Segment 4	Parity (3,4)
Segment	6	Parity (5,6)	Segment 5	Segment 8	Parity (7,8)	Segment 7
Parity (9,	10)	Segment 9	Segment 10	Parity (11, 12)	Segment 11	Segment 12

RAID 6

Similar to RAID 5, RAID 6 also provides block-level striping with parity data distrib- uted across all drives, except that there are two parity blocks per stripe instead of just one. A RAID 6 configuration can survive the loss of any two drives in a virtual drive without losing data and requires a minimm of 3 drives. The following illustra- tion provides a visual example of a RAID 6 virtual drive group.

Note: In the following RAID 6 illustration, the P drives represent the RAID 5 parity scheme. The Q drives represent the second set of parity drives.

RAID 6

Drive A	Drive B	Drive C	Drive D	Drive E	Drive F
Segment 1	Segment 2	Segment 3	Segment 4	Parity (P1-P4)	Parity (Q1-Q4)
Segment 6	Segment 7	Segment 8	Party (P5-P8)	Parity (Q5-Q8)	Segment 5
Segment 11	Segment 12	Parity (P9-P12)	Party (Q9-Q12)	Segment 9	Segment 10
Segment 16	Parity (P13-P16)	Parity (Q13-Q16)	Segment 13	Segment 14	Segment 15
Parity (P17-P20)	Parity (Q17-Q20)	Segment 17	Segment 18	Segment 19	Segment 20

RAID 6 Example

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