Product specifications

Array Expansion
8-1
Array Expansion
The array expansion functions allow you to expand storage capacity
without the cost of buying new equipment. Expansion can be
completed on-line while the system is serving host I/Os.
8.1 Overview
What is RAID Expansion and how does it work?
Before the invention of RAID Expansion, increasing the capacity of
a RAID system meant backing up all data in the disk array, re-
creating the disk array configuration with new drives, and then
restoring data back into system.
Infortrend’s RAID Expansion technology allows users to expand a
logical drive by adding new drives, or replacing drive members
with drives of larger capacity. Replacing is done by copying data
from the original members onto larger drives; the smaller drives can
then be replaced without powering down the system.
8.2 Notes on Expansion
1. Added Capacity:
When a new drive is added to an existing logical drive, the
capacity brought by the new drive appears as a new partition.
For example, if you have 4 physical drives (36GB each) in a
logical drive, and each drive’s maximum capacity is used, the
capacity of the logical drive will be 108GB. (One drive’s capacity
is used for parity, e.g., RAID 3). When a new 36GB drive is
Chapter
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