ZyXEL NSA-2400 Guia Do Utilizador

Chapter 7 Storage Screens

NSA-2400 User’s Guide

RAID 1 creates an exact copy (or mirror) of a set of data on another disk. This is useful when 
data backup is more important than data capacity. The following figure shows two disks in a 
single RAID 1 volume with mirrored data. Data is duplicated across two disks, so if one disk 
fails, there is still a a copy of the data.

 

As RAID 1 uses mirroring and duplexing, a RAID 1 volume needs an even number of disks 
(two or four for the NSA).

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When you use RAID 1 on the NSA-2400, you MUST use disks 1 and 2 in one 
RAID volume and/or disks 3 and 4 in the other; you cannot have disks 1 and 3 
in the same RAID volume for example.

RAID 1 capacity is limited to the size of the smallest disk in the RAID array. For example, if 
you have two disks of sizes 150 GB and 200 GB respectively in one RAID 1 volume, then the 
maximum capacity is 150 GB and the remaining space (50 GB) is unused.

Typical applications for RAID 1 are those requiring high fault tolerance without need of large 
amounts of storage capacity or top performance, for example, accounting and financial data, 
small database systems, and enterprise servers.

Table 40   RAID 1