User guide
Table Of Contents
- Title Page
- Table of Contents
- About this User Guide
- Introducing the 3ware® SATA RAID Controller
- Getting Started with Your 3ware RAID Controller
- First-Time RAID Configuration Using 3BM
- Driver Installation
- Driver Installation Under Windows
- Driver Installation Under Linux
- Obtaining 3ware Linux Drivers
- Driver Installation Under Red Hat Linux or Fedora Core 5
- Materials required
- Creating a Red Hat Linux Driver Diskette
- Installing the 3ware Kernel Driver Module while Installing Red Hat Linux on a New Unit
- Installing the 3ware Kernel Driver Module on a Red Hat or Fedora Core Linux System that Boots From a Different Device
- About Variables In the Kernel Driver Module Installation Instructions
- Driver Installation Under SuSE Linux
- Compiling a 3ware Driver for Linux
- Driver Installation Under FreeBSD
- 3ware BIOS Manager 2 (3BM 2) Introduction
- 3DM 2 (3ware Disk Manager) Introduction
- Configuring Your Controller
- Configuring Units
- Configuring a New Unit
- Creating a Hot Spare
- Naming a Unit
- Setting Unit Policies
- Changing An Existing Configuration by Migrating
- Deleting a Unit
- Removing a Unit
- Moving a Unit from One Controller to Another
- Adding a Drive
- Removing a Drive
- Rescanning the Controller
- Maintaining Units
- Checking Unit and Drive Status through 3DM
- About Degraded Units
- About Inoperable Units
- Alarms, Errors, and Other Events
- Background Tasks
- Scheduling Background Tasks
- Locating a Drive by Blinking Its LED
- Maintaining Your Controller
- Determining the Current Version of Your 3ware Driver
- Updating the Firmware and Driver
- Downloading the Driver and Firmware
- Updating the Firmware Through 3DM 2
- Updating the 3ware Driver and Firmware Under Windows
- Using the Update Utility With Multiple Controllers
- Updating the 3ware Driver Under Windows XP
- Updating the 3ware Driver Under Red Hat or Fedora Core
- Updating the 3ware Driver Under SuSE
- Updating the 3ware Driver Under FreeBSD
- Updating the Firmware Under Linux and FreeBSD
- Viewing Battery Information
- Testing Battery Capacity
- 3DM 2 Reference
- Troubleshooting
- Appendices
- Index
Chapter 1. Introducing the 3ware® SATA RAID Controller
12 3ware Serial ATA RAID Controller User Guide
Using Drive Capacity Efficiently
To make the most efficient use of drive capacity, it is advisable to use drives
of the same capacity in a unit. This is because the capacity of each drive is
limited to the capacity of the smallest drive in the unit.
The total unit capacity is defined as follows:
Through drive coercion, the capacity used for each drive is rounded down so
that drives from differing manufacturers are more likely to be able to be used
as spares for each other. The capacity used for each drive is rounded down to
the nearest GB for drives under 45 GB (45,000,000,000 bytes), and rounded
down to the nearest 5 GB for drives over 45 GB. For example, a 44.3 GB
drive will be rounded down to 44 GB, and a 123 GB drive will be rounded
down to 120 GB. For more information, see the discussion of drive coercion
under “Creating a Hot Spare” on page 103.
5RAID 6
RAID 5 with hot spare
RAID 10 with hot spare
Combination of RAID 0, RAID 1, hot spare, single disk
6 or more RAID 6
RAID 6 with hot spare
RAID 50
Combination of RAID 0, 1, 5, 6,10, hot spare, single disk
Table 5: Drive Capacity
RAID Level Capacity
Single Disk Capacity of the drive
RAID 0 (number of drives) X (capacity of the smallest drive)
RAID 1 Capacity of the smallest drive
RAID 5 (number of drives - 1) X (capacity of the smallest drive)
Storage efficiency increases with the number of disks:
storage efficiency = (number of drives -1)/(number of drives)
RAID 6 (number of drives - 2) x (capacity of the smallest drive)
RAID 10 (number of drives / 2) X (capacity of smallest drive)
RAID 50 (number of drives - number of groups of drives) X (capacity of the
smallest drive)
Table 4: Possible Configurations Based on Number of Drives
# Drives Possible RAID Configurations