Users guide

21 Intel® RAID Software User Guide
5 RAID 5 provides high data throughput, especially for large files. Use this RAID level for
any application that requires high read request rates, but low write request rates, such
as transaction processing applications, because each drive can read and write
independently. Since each drive contains both data and parity, numerous writes can
take place concurrently. In addition, robust caching algorithms and hardware based
exclusive-or assist make RAID 5 performance exceptional in many different
environments.
Parity generation can slow the write process, making write performance significantly
lo
wer for RAID 5 than for RAID 0 or RAID 1. Disk drive performance is reduced when a
drive is being rebuilt. Clustering can also reduce drive performance. Environments with
few processes do not perform as well because the RAID overhead is not offset by the
performance gains in handling simultaneous processes.
6 RAID 6 works best when used with data that requires high reliability, high request rates,
an
d high data transfer. It provides high data throughput, data redundancy, and very
good performance. However, RAID 6 is not well suited to tasks requiring a lot of writes.
A RAID 6 virtual disk has to generate two sets of parity data for each write operation,
which results in a significant decrease in performance during writes. Disk 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.
10 RAID 10 works best for data storage that need the
enhanced I/O performance of RAID
0 (striped arrays), which provides high data transfer rates. Spanning increases the size
of the virtual volume and improves performance by doubling the number of spindles.
The system performance improves as the number of spans increases (the maximum
number of spans is eight). As the storage space in the spans is filled, the system stripes
data over fewer and fewer spans and RAID performance degrades to that of a RAID 1
or RAID 5 array.
50 RAID 50 works best when used with data that requires high reliability, high request
rates,
and high data transfer. It provides high data throughput, data redundancy, and
very good performance. Spanning increases the size of the virtual volume and
improves performance by doubling the number of spindles. The system performance
improves as the number of spans increases (the maximum number of spans is eight).
As the storage space in the spans is filled, the system stripes data over fewer and fewer
spans and RAID performance degrades to that of a RAID 1 or RAID 5 array.
60 RAID 60 works best when used with data that requires high reliability, high request
rates,
and high data transfer. It provides high data throughput, data redundancy, and
very good performance. Spanning increases the size of the virtual volume and
improves performance by doubling the number of spindles. The system performance
improves as the number of spans increases (the maximum number of spans is eight).
As the storage space in the spans is filled, the system stripes data over fewer and fewer
spans and RAID performance degrades to that of a RAID 1 or RAID 6 array.
RAID 60 is not well suited to tasks requiring a lot of
writes. A RAID 60 virtual disk has to
generate two sets of parity data for each write operation, which results in a significant
decrease in performance during writes. Disk 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
Lev
el
Performance