Outline of Functions
17
The RAID function makes it possi
b
le to improve the HDD
'
s tolerance
to errors.
This product is e
q
uipped
w
ith the RAID6 mode that can recover
image data
w
hen t
w
o HDDs fail, in addition to the RAID5 mode that
can recover image data (RAID6 has t
w
o sets of error correcting
code data). This prevents loss of recorded image data on large
volume HDDs (refer to the Setup Instructions (PDF file).
Note:
•
To use the RAID5 mode you need to connect 3 or more HDDs,
the RAID6 mode re
q
uires 4 or more HDDs.
•
Theoretical volume
w
hen RAID5 mode ena
b
led
Theoretical volume = HDD
w
ith smallest capacity in the unit x
(num
b
er of HDDs in the unit
−
1)
•
Theoretical volume
w
hen RAID6 mode ena
b
led
Theoretical volume = HDD
w
ith smallest capacity in the unit x
(num
b
er of HDDs in the unit
−
2)
•
The capacity of the HDDs that are installed may
b
e a fe
w
percents smaller.
The image and audio data recorded on the HDDs is encrypted. The
image and audio data on the HDDs cannot
b
e played except on the
recorder.
The recorder uses RSA
®
BSAFE
™
soft
w
are from RSA Security Inc.
HDD Fault Tolerance System
Encryptin
g
Data Recorded on the HDDs
C 4
C 3
C 2
Q 1
B 4
B 3
Q 2
P 1
A 4
Q 3
P 2
C 1
Q 4
P 3
B 2
B 1
P 4
A 3
A 2
A 1
RAID 6
ND400_Basic.book 17 ページ ２００８年４月８日 火曜日 午後３時５９分
