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MegaRAID SAS Software User GuideChapter 2: Introduction to RAID
| RAID Levels
Figure 10: Example of Distributed Parity across Two Blocks in a Stripe (RAID 6)
2.5.7 RAID 00 A RAID 00 drive group is a spanned drive group that creates a striped set from a series
of RAID 0 drive groups. RAID 00 does not provide any data redundancy, but, along with
RAID 0, does offer the best performance of any RAID level. RAID 00 breaks up data into
smaller segments and then stripes the data segments across each drive in the drive
groups. The size of each data segment is determined by the stripe size. RAID 00 offers
high bandwidth.
NOTE: RAID level 00 is not fault tolerant. If a drive in a RAID 0 drive group fails, the whole
virtual drive (all drives associated with the virtual drive) will fail.
By breaking up a large file into smaller segments, the RAID controller can use both SAS
drives and SATA drives to read or write the file faster. RAID 00 involves no parity
calculations to complicate the write operation. This makes RAID 00 ideal for
applications that require high bandwidth but do not require fault tolerance. Table11
provides an overview of RAID 00. Figure11 provides a graphic example of a RAID 00
drive group.
Segment 1
Segment 6
Segment 2
Segment 7
Segment 3
Segment 8
Segment 4
Parity (P5-P8)
Parity (P1-P4)
Parity (Q5-Q8)
Parity (Q9–Q12)
Parity (Q1-Q4)
Segment 5
Note: Parity is distributed across all drives in the drive group.
Segment 10
Parity (P9-P12)
Segment 9
Segment 12
Segment 11
Segment 16
Parity (P17-P20)
Parity (P13-P16)
Segment 19
Segment 15
Segment 17
Segment 13
Segment 18
Segment 14
Parity (Q17-Q20)
Parity (Q13-Q16)
Segment 20
Table 11: RAID 00 Overview
Uses Provides high data throughput, especially for large files. Any environment
that does not require fault tolerance.
Strong Points Provides increased data throughput for large files.
No capacity loss penalty for parity.
Weak Points Does not provide fault tolerance or high bandwidth.
All data lost if any drive fails.
Drives 2 through 256
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