Basic Disk Configuration Concepts; Raid; Volumes - NETGEAR RNDU4000-100NAS Software Manual

Basic Disk Configuration Concepts

To get the most out of your ReadyNAS storage system, it is helpful to understand some disk
configuration concepts. Understanding these concepts is the first step to making good
decisions about how to configure, manage, and use your ReadyNAS storage system.
You can configure your storage system's hard disks in a variety of ways. The most common
way to configure disks is using one of the many RAID technologies.

RAID

RAID is short for redundant array of independent disks. RAID is a storage technology that
balances data protection, system performance, and storage space by determining how the
storage system distributes data. Many different ways of distributing data have been
standardized into various RAID levels. Each RAID level offers a tradeoff of data protection,
system performance, and storage space. For example, one RAID level might improve data
protection but reduce storage space. Another RAID level might increase storage space but
also reduce system performance.
Your ReadyNAS storage system supports X-RAID2
architecture that is easy to administer, and Flex-RAID, which allows you to format your disks
in a variety of industry-standard RAID levels.

Volumes

In the most general sense, volumes are data storage devices. Your computer treats an
internal hard drive as a volume. It also treats a portable USB thumb drive as a volume.
Volumes can be either physical or logical. Usually, the term physical volume refers to a hard
disk drive. When this term is used in this way, a two-bay storage system can have up to two
physical volumes (hard disk drives), a four-bay storage system can have up to four physical
volumes (hard disk drives), and a six-bay storage system can have up to six physical
volumes.
The term logical volume refers to the way that you divide, or partition, your storage space, for
example:
• Each logical volume can correspond to a hard disk drive
• A logical volume can be made up of more than one hard disk drive
• A hard disk drive can be divided into multiple logical volumes
In this manual, the term volume refers to a logical volume. In this manual, the terms hard disk
drive and disk refer to a physical volume.
ReadyNAS for Home RAIDiator 4.2
Disk Configuration
17
TM
, a proprietary single-volume RAID