StorCase Technology InfoStation 12-Bay 4U Ultra320/SATA - Manual (Page 79)

66 RAID Controller Configuration
StorCase Technology, Inc. InfoStation 12-Bay RAID User's Guide - Rev. D00
Table 6: RAID Level Comparisons
Array Management
The unique RAID Controller array management firmware utilizes multi-tasking real-time kernel
technology to manage the controller. Additional features are real-time load analysis, online
diagnostics, event logging and broadcasting, and device inventory management.
RAID Levels
The RAID Controller supports RAID levels 0, 0+1, 1, 3, 5, 30, and 50. Depending on the
application that will be used, each RAID level offers a difference in performance, functionality,
and fault tolerance as shown in Table 6.
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 5 3
Block-level data striping
with distributed parity
Best cost and performance
for transaction-oriented
networks
Very high performance and
data protection
Supports multiple
simultaneous read/writes
Can also be optimized for
large, sequential requests
Write performance is slower than
RAID 0 or RAID 1
RAID 10
RAID 0/1
3
Combination of
RAID 0 (data striping)
and RAID 1 (mirroring)
Highest performance and
data protection (can tolerate
multiple drive failures)
High redundancy costs - twice the
storage is capacity required
RAID 30 6
Data striping across two
RAID 3 arrays
*See RAID 3
Allows one drive failure in
each array
High redundancy
RAID 50 6
Data striping across two
RAID 5 arrays
*See RAID 5
Allows one drive failure in
each array
High redundancy
* See RAID 3
High redundancy costs - twice the
storage is capacity required
* See RAID 5
High redundancy costs - twice the
storage is capacity required