X-Raid2 - NETGEAR RND4000v2 Software Manual

ReadyNAS for Home RAIDiator 5.3

X-RAID2

X-RAID2 is a RAID technology that expands automatically and is available only on
ReadyNAS systems. With X-RAID2, you do not need to know intricate details about RAID to
administer your system. X-RAID2 allows you to add storage space without reformatting your
drives or moving your data to another location. Because the expansion happens online, you
can continue to use your ReadyNAS system while the underlying volume capacity increases.
Because X-RAID2 uses a single-volume architecture, if you configure your hard disk drives to
use X-RAID2, your storage system has only one volume that is made up of all installed hard
disk drives. X-RAID2's single-volume architecture has two major advantages:
• Easy system management
• Auto expansion
With typical RAID formatting, to add disks or replace disks with larger capacity disks, you
must back up the data to another system, add a disk, reformat the RAID volume, and restore
the data to the new RAID volume. With X-RAID2, none of those administrative tasks are
required. Instead, with X-RAID2, your volume automatically expands to accommodate
additional disks or larger capacity disks when you replace smaller capacity disks.
With X-RAID2, you can start out with one hard disk, add a second disk for data protection,
then add more disks for additional capacity, and X-RAID2 accommodates the new disks
automatically. You can replace existing disks with larger capacity disks and X-RAID2
automatically accommodates the new disks.
X-RAID2 requires a minimum of two hard disks to provide protection against disk failure. If
you have a one-disk X-RAID2 storage system and want protection from disk failure, you must
add a second disk at least as large as the first. It can be added while the system is running.
X-RAID2 uses the first disk to store data, and the second disk to store parity information that
allows it to re-create data if a disk fails in this two-disk system, the usable storage space is
one disk. In a three-disk system, the usable storage space is two disks, and in a four-disk
volume, the usable storage space is three disks.
Disk Configuration
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