StorCase Technology Fibre-to-SCSI Single RAID - Manual (Page 144)

132 Appendix B - Array Basics
StorCase Technology, Inc. S10C100 User's Guide - Rev. A01
RAID
Level
Minimum #
of Drives
Description Pros Cons
RAID 0 2 Data striping
without
redundancy
Highest
performance
No data protection - if
one drive fails, all data
is lost
RAID 1 2 Disk mirroring Very high
performance and
data protection
Good write
performance
High redundancy
costs - twice the
storage capacity is
required
RAID 3 3 Block-level data
striping with
dedicated parity
drive
Excellent
performance for
large, sequential
data requests
Poorly suited for
transaction-oriented
network applications
Single parity drives do
not support multiple,
simultaneous read/write
requests
RAID 4
(Not
widely
used)
3 Data striping
supports multiple
simultaneous read
requests
Write requests suffer
from same single parity
drive bottlenecks as
RAID 3
RAID 5 offers equal
data protection and
better performance at
same cost
Block-level data
striping with
dedicated parity
drive
IFS_53
Table B-1: RAID Level Comparisons
Mixing Disks on Different RAID Controller Channels
The RAID Controller Module hasfour drive channels. An array can consist of disks on different
channels of the same RAID controller.
Comparing RAID Levels
Table B-1 illustrates the differences between the various RAID levels.