ZyXEL Communications NSA210 - Manual (Page 155)

Chapter 7 Storage
NSA210 User’s Guide
155
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.
RAID 1 and Data Protection
If a hard disk fails and you’re using a RAID 1 volume, then your data will still be
available (but at degraded speeds until you replace the hard disk that failed and
resynchronize the volume). However, RAID cannot protect against file corruption,
virus attacks, files incorrectly deleted or modified, or the NSA malfunctioning.
Here are some suggestions for helping to protect your data.
• Place the NSA behind a hardware-based firewall. It should have stateful packet
inspection, IDP (Intrusion Detection and Prevention), and anti-virus (like
ZyXEL’s ZyWALL UTM products for example).
• Use anti-virus software on your computer to scan files from others before saving
the files on the NSA.
Keep another copy of important files (preferably in another location).
7.5.3 Volume Status
You (the administrator) can see the status of a volume in the Status or Storage
screens.
The NSA has the following classifications for the status of a volume:
• Healthy if all disks in the volume are OK and the file system is functioning
properly.
• OK means the USB connected device is functioning properly.
• Resync when you create a RAID 1 volume.
• Recovering appears when repairing a RAID 1 volume. (A RAID 1 volume was
once degraded, but you have installed a new disk and the NSA is restoring the
RAID 1 volume to a healthy state.)
• Degraded when a volume is currently down, but can be fixed. Data access may
be slower from a degraded volume, so it’s recommended that you replace the
faulty disk and repair the volume as soon as you can.
• Inactive when a disk is missing from a two-disk JBOD volume. The volume is
unusable. If you removed one of the disks you should be able to re-install it and
use the volume again (as long as you did not change anything on the disk). If a
disk has failed, you need to replace it and re-create the whole volume. All data
will be lost. See page 339 for how to install or replace a hard drive.
• Down when a volume is down and can not be fixed.
A down RAID volume cannot be used until you repair or replace the faulty disk(s)
in the volume. Degraded means one of the disks in the RAID volume is not