Volume Status; Resynchronizing A Raid 1 Volume - ZyXEL Communications NSA-220 User Manual

Chapter 6 Storage Screens
• Choose RAID 0 if performance matters more than data security. RAID 0 has the
fastest read and write performance but if one disk fails you lose all your data on the
volume. It has fast performance as it can read and write to two disks simultaneously.
Performance may matter more than data security to gamers for example. This method
may also be acceptable for data that is already backed up somewhere else.
• Choose RAID 1 if data security is more important than performance. Since RAID 1
mirrors data onto a second disk, you can recover all data even if one disk fails, but the
performance is slower than RAID 0.

6.3.2 Volume Status

You (the administrator) can see the status of a volume in the Status, Storage > Overview or
Storage > Volume 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 your USB disk was formatted as NTFS. It is read-only for the NSA.
• Resync when you create or repair a RAID volume.
• 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 RAID 0 volume or 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
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• 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 available but the volume
can still be used. For a degraded volume, you should replace the faulty disk as soon as possible
to obtain previous performance. See your Quick Start Guide for more information on replacing
a disk.
If it's down, then the only indication is that you can no longer transfer files to/from the shares
in the down volume. If it's degraded, then file transfer to/from the shares in the degraded
volume will be slower.
There is no explicit message from CIFS that tells users their volume is
degraded or down.

6.3.3 Resynchronizing a RAID 1 Volume

Resynchronizing a RAID 1 volume is done block-by-block, so the time it takes depends more
on the size of your hard drive(s) than the amount of data you have on them.
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for how to install or replace a hard drive.
NSA-220 User's Guide