Lenovo ThinkServer RD240 MegaRAID SAS Software User Guide - Page 59
RAID Configuration Strategies, RAID 60 Level Virtual Drive, Table 2.12
![]() |
View all Lenovo ThinkServer RD240 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 59 highlights
Table 2.12 RAID 60 Overview Weak Points Drives Not well suited to tasks requiring lot of writes. A RAID 60 virtual drive has to generate two sets of parity data for each write operation, which results in a significant decrease in performance during writes. Drive performance is reduced during a drive rebuild. Environments with few processes do not perform as well because the RAID overhead is not offset by the performance gains in handling simultaneous processes. RAID 6 costs more because of the extra capacity required by using two parity blocks per stripe. A minimum of 8 Figure 2.12 shows a RAID 6 data layout. The second set of parity drives are denoted by Q. The P drives follow the RAID 5 parity scheme. Figure 2.12 RAID 60 Level Virtual Drive RAID 60 Segment 1 Segment 8 Parity (Q11-Q12) Parity (P15-P16) Segment 2 Parity (Q3-Q4) Parity (P11-P12) Segment 15 Parity (Q1-Q2) Parity (P3-P4) Segment 11 Segment 16 Parity (P1-P2) Segment 7 Segment 12 Parity (Q15-Q16) Segment 3 Segment 6 Parity (Q9-Q10) Parity (P13-P14) Segment 4 Parity (Q5-Q6) Parity (P9-P10) Segment 13 Parity (Q3-Q4) Parity (P5-P6) Segment 9 Segment 14 Parity (P3-P4) Segment 5 Segment 10 Parity (Q13-Q14) RAID 6 RAID 0 Note: Parity is distributed across all drives in the drive group. RAID 6 2.6 RAID Configuration Strategies The most important factors in RAID drive group configuration are: • Virtual drive availability (fault tolerance) • Virtual drive performance • Virtual drive capacity You cannot configure a virtual drive that optimizes all three factors, but it is easy to choose a virtual drive configuration that maximizes one factor at the expense of another factor. For example, RAID 1 (mirroring) provides excellent fault tolerance, but requires a redundant drive. The following subsections describe how to use the RAID levels to RAID Configuration Strategies 2-27
![](/manual_guide/products/lenovo-thinkserver-rd230-megaraid-sas-software-user-guide-7a323ec/59.png)