User`s guide
Table Of Contents
- About This Guide
- Kit Contents and System Requirements
- About Your RAID Controller
- Standard RAID Controller Features
- Adding Enhanced Features
- Adding a Battery Backup Module
- Upgrading the Controller Firmware
- About the Adaptec 3085
- About the Adaptec 3405
- About the Adaptec 3805
- About the Adaptec 31205
- About the Adaptec 31605
- About the Adaptec 4000
- About the Adaptec 4800SAS
- About the Adaptec 4805SAS
- About the Adaptec 2420SA
- About the Adaptec 2820SA
- About the Adaptec 2130SLP
- About the Adaptec 2230SLP
- Getting Started
- Installing the Controller and Disk Drives
- Creating a Bootable Array
- Installing the Driver and an Operating System
- Installing the Driver on an Existing Operating System
- Managing Your Storage Space
- Solving Problems
- Introduction to Serial Attached SCSI
- Understanding RAID
- Using the Adaptec RAID Configuration Utility
- Using the Array Configuration Utility for DOS
- Using the Adaptec Flash Utility
- Adaptec Serial Controller LED and I2C Connector Reference
- Adaptec 2420SA Activity LED and I2C Connector Specification
- Adaptec 2820SA Activity LED and I2C Connector Specification
- Adaptec 3085 LED and I2C Connector Specification
- Adaptec 3405 LED and I2C Connector Specification
- Adaptec 3805 LED and I2C Connector Specification
- Adaptec 31205 LED and I2C Connector Specification
- Adaptec 31605 LED and I2C Connector Specification
- Adaptec 4800SAS LED and I2C Connector Specification
- Adaptec 4805SAS LED and I2C Connector Specification
- Safety Information
- Technical Specifications
- Index
Appendix B: Understanding RAID ● 83
Selecting the Best RAID Level
Use this table to select the RAID levels that are most appropriate for the logical drives on your storage space, based on
the number of available disk drives and your requirements for performance and reliability.
Disk drive usage, read performance, and write performance depend on the number of drives in the logical drive. In
general, the more drives, the better the performance.
RAID Level Redundancy
Disk Drive
Usage
Read
Performance
Write
Performance
Built-in Hot
Spare
Minimum
Disk Drives
RAID 0 No 100%
No 2
RAID 1 Yes 50%
No 2
RAID 1E Yes 50%
No 3
RAID 10 Yes 50%
No 4
RAID 5 Yes 67 – 94%
No 3
RAID 5EE Yes 50 – 88%
Yes 4
RAID 50
1
1
Because they support four disk drives only, the Adaptec 2420SA RAID controller can’t support RAID 50 or RAID 60
arrays.
Yes 67 – 94%
No 6
RAID 6 Yes 50 – 88%
No 4
RAID 60
1
Yes 50 – 88%
No 8