NETGEAR ReadyNAS Pro Business Edition - Manual (Page 14)

ReadyNAS Pro Business Edition User Guide
1-2 Getting Acquainted
v1.3, November 2008
entire system for abnormal situations or part failures and e-mails system alerts to the network
administrator. In addition, the Frontview Add-on SDK provides developers the tools for uniquely
extending ReadyNAS capabilities. For a full list of what is new compared with existing
ReadyNAS systems, see
ReadyNAS Specifications on ReadyNAS.com.
What Are the Benefits of X-RAID and X-RAID2?
Shipping in volume since 2004, X-RAID is a proven patent-pending technology that is available
only on ReadyNAS. ReadyNAS Pro introduces X-RAID2, the 2
nd generation version of X-RAID.
X-RAID Is Expandable RAID
RAID stands for Redundant Array of Independent Disks, which is a way of protecting your data in
case of a disk failure. The X in X-RAID stands for “expandable”; X-RAID is expandable RAID.
X-RAID technology simplifies volume management. What most people want to do with their data
volumes over time is either add redundancy or expand them without the headaches usually
associated with doing so. By using simple rules, X-RAID hides the complexities yet still provides
volume management features previously available only in enterprise-level storage solutions.
X-RAID Simplifies Redundancy
To maintain redundancy from disk failure, X-RAID requires a one-disk overhead. In a two-disk X-
RAID volume, the usable capacity is one disk, in a three-disk volume the usable capacity is two
disks, in a four-disk volume, the usable capacity is three disks, etc.
No Redundancy with a Single Disk but Easy to Add Disks with X-RAID
Even with RAID, there is no data redundancy with one disk; if that disk fails, your data is lost. If
you have a one-disk ReadyNAS and want protection from disk failure, you have to add a 2nd disk
that is at least as large as the first. It can be ‘hot-added’ while the ReadyNAS is running.
Whenever you add or replace a disk, the ReadyNAS will initialize it, scanning to make sure the
disk is good. Once added, your 2nd disk will synch with the 1st disk. Depending on the disk size,
the synch may take anywhere from 30 minutes to several hours. The sync occurs in the
background so you can still keep on working with the ReadyNAS during this time.
After the sync completes, your data volume is now redundant, meaning if one of the disks fails, the
other disk still contains the data, and thus your data is now fully protected from a disk failure.