ZyXEL Communications UNS Series ユーザーズマニュアル

UNS Series User’s Guide

This chapter provides information for Physical Disk in Storage Configuration. 

The section covers a brief introduction to storage methods and management of storage pools and 
disks. 

The following is a reference guide to help you select a storage method for the various number of 
disks supported on the UNS Series. Redundant Array of Independent Disks (RAID) is a storage 
method of storing data on multiple disks to provide a combination of greater capacity, reliability, 
and/or speed. 

RAID 0 provides a high level of disk I/O performance without fault tolerance. RAID 0 does not have 
a minimum hard drive requirement.

RAID 1 provides high data reliability (100% data redundancy) at a reduced performance speed. 
RAID 1 requires a minimum of two drives. 

RAID 5 distributes data across multiple disks while protecting the data against a single disk failure. 
In the event of a failure of any disk member, the parity will be used to rebuild the contents of the 
failed drive on the new one. RAID 5 requires a minimum of three drives. 

RAID 6 distributes the data across multiple disks and protects against a two-disk failure. This RAID 
level is designed for mission critical applications. RAID 5 and 6 display the same performance level. 
RAID 6 requires a minimum of four drives. 

RAID 50 is a combination of RAID 5 and RAID 0 distributed parity (RAID 5) and data striping across 
multiple disks (RAID 0). RAID 50 offers high reliability and transfer rate aggregation. RAID 50 
requires a minimum of six drives.