Acer Series 520 Network Card User Manual


 
RAID 5 3-5
Copyright © 2002 by LSI Logic Corporation. All rights reserved.
Figure 3.3 shows a RAID 5 array with six disk drives.
Figure 3.3 RAID 5 Array
Uses Provides high data throughput, especially for large files. Use
RAID 5 for transaction processing applications, because each
drive can read and write independently. If a drive fails, the
MegaRAID SCSI 320-0 uses the parity data to recreate all
missing information. Use also for office automation and online
customer service that requires fault tolerance. Use for any
application that has high read request rates but low write
request rates.
Strong Points Provides data redundancy and good performance in most
environments
Weak Points Disk drive performance is reduced if a drive is being rebuilt.
Environments with few processes do not perform as well
because the RAID overhead is not offset by the performance
gains in handling simultaneous processes.
Drives 3 to 30
The MegaRAID SCSI 320-0 controller supports one or two
SCSI channels, with up to 15 SCSI devices on each channel.
Segment 1
Segment 7
Parity (9–12)
Segment 2
Segment 8
Segment 3
Segment 9
Parity (5–8)
Segment 4
Segment 10
Disk 1 Disk 2 Disk 3 Disk 4 Disk 5 Disk 6
Segment 5
Segment 11
Parity (1–4)
Segment 6
Segment 12
Data Flow
Note: Parity is distributed
across drives in the array.
MegaRAID Controller