Avago Technologies MegaRAID Fast Path Software - Manual (Page 39)

LSI Corporation Confidential | July 2011 Page 39
MegaRAID SAS Software User Guide Chapter 2: Introduction to RAID | RAID Levels
Table 13 provides an overview of RAID 50.
Figure 13: RAID 50 Level Virtual Drive
2.5.10 RAID 60 RAID 60 provides the features of both RAID 0 and RAID 6, and includes both parity and
disk striping across multiple drive groups. RAID 6 supports two independent parity
blocks per stripe. A RAID 60 virtual drive can survive the loss of two drives in each of the
RAID 6 sets without losing data. RAID 60 is best implemented on two RAID 6 drive
groups with data striped across both drive groups.
RAID 60 breaks up data into smaller blocks and then stripes the blocks of data to each
RAID 6 disk set. RAID 6 breaks up data into smaller blocks, calculates parity by
performing an exclusive-or on the blocks, and then writes the blocks of data and parity
to each drive in the drive group. The size of each block is determined by the stripe size
parameter, which is set during the creation of the RAID set.
Table 13: RAID 50 Overview
Uses Appropriate when used with data that requires high reliability, high request
rates, high data transfer, and medium-to-large capacity.
Strong points Provides high data throughput, data redundancy, and very good
performance.
Weak points Requires 2 times to 8 times as many parity drives as RAID 5.
Drives 8 spans of RAID 5 drive groups containing 3 to 32 drives each (limited by the
maximum number of devices supported by the controller)
Segment 1 Segment 2
Segment 5 Segment 6
RAID 0
RAID 50
Parity (1,2) Segment 3 Segment 4
Segment 8 Segment 7
Segment 9 Segment 10 Segment 11 Segment 12
Parity (5,6)
Parity (9,10) Parity (11,12)
Parity (7,8)
Parity (3,4)
RAID 5 RAID 5