User Guide

X-RAID

X-RAID is an autoexpandable RAID technology that is available only on ReadyNAS systems.With X-RAID,

you do not need to know intricate details about RAID to administer your system. X-RAID 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 volume capacity

increases.

Because X-RAID is a single-volume architecture, if you configure your hard disk drives to use X-RAID, your

storage system includes only one volume that is made up of all installed hard disk drives. X-RAID’s

single-volume architecture provides two major advantages:

• Easy system management

• Auto expansion

Adding disks to a Flex-RAID formatted system is more complex. Disks must be added in ways compatible

with the RAID level, or 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-RAID, none of those administrative tasks are required.

Instead, with X-RAID, your volume automatically expands to accommodate additional disks or larger-capacity

disks.

With X-RAID, you can start out with one hard disk, add a second disk for data protection, and add more

disks for additional storage capacity. X-RAID accommodates the new disks automatically.You can replace

existing disks with larger-capacity disks and X-RAID automatically accommodates the new disks.

X-RAID requires a minimum of two hard disks to provide protection against disk failure. If you use a ReadyNAS

storage system with only one disk and want protection from disk failure, you must add a second disk that

is at least as large as the first. It can be added while the system is running.

X-RAID uses the capacity of one disk for data storage and reserves the capacity of a second disk for data

protection, which allows the volume to recreate data if a disk fails. In a two-disk system, the usable storage

space is one disk. In a three-disk system, the usable storage space is two disks. In general, the total capacity

of your storage system equals the capacity of all your disks minus the capacity of one disk.

The following figure illustrates how X-RAID uses new disks.

Volume Configuration

ReadyNAS OS 6.7