451
8 Appendix A HDD Capacity Calculation
Calculate total capacity needed by each device according to video recording (video recording type and
video file storage time).
Step 1: According to Formula (1) to calculate storage capacity
i
q
that is the capacity of each channel
needed for each hour, unit Mbyte.
1024
3600
8
i
i
d
q
(1)
In the formula:
i
d
means the bit rate, unit Kbit/s
Step 2: After video time requirement is confirmed, according to Formula (2) to calculate the storage
capacity
i
m
, which is storage of each channel needed unit Mbyte.
i
m
=
i
q
×
i
h
×
i
D
(2)
In the formula:
i
h
means the recording time for each day (hour)
i
D
means number of days for which the video shall be kept
Step 3: According to Formula (3) to calculate total capacity (accumulation)
T
q
that is needed for all
channels in the device during
scheduled video recording
.
c
i
i
T
m
q
1
(3)
In the formula:
c
means total number of channels in one device
Step 4: According to Formula (4) to calculate total capacity (accumulation)
T
q
that is needed for all
channels in device during
alarm video recording (including motion detection)
.
c
i
i
T
m
q
1
×
a%
(4)
In the formula:
a%
means alarm occurrence rate
Summary of Contents for NVR21-S2 SERIES
Page 1: ...Dahua Network Video Recorder User s Manual V 4 3 0...
Page 138: ...124 Figure 3 5 3 6 6 NVR42N Series Please refer to Figure 3 6 for connection sample Figure 3 6...
Page 142: ...128 Figure 3 11 3 6 12 NVR42V 8P Series Please refer to Figure 3 12 for connection sample...
Page 143: ...129 Figure 3 12...
Page 157: ...143 Figure 4 15 Step 2 Click device display edit interface See Figure 4 16...
Page 220: ...206 Figure 4 93 Figure 4 94...
Page 240: ...226 Figure 4 110 Figure 4 111 Figure 4 112...
Page 251: ...237 Figure 4 123 Figure 4 124...
Page 253: ...239 Figure 4 126 Click draw button to draw the zone See Figure 4 127...
Page 257: ...243 Figure 4 130 Click Draw button to draw a zone See Figure 4 131 Figure 4 131...
Page 262: ...248 Figure 4 136 Click draw button to draw the zone See Figure 4 137...
Page 275: ...261 Figure 4 148 Figure 4 149...
Page 276: ...262 Figure 4 150 Figure 4 151...
Page 387: ...373 Figure 5 60 Figure 5 61...
Page 388: ...374 Figure 5 62 Figure 5 63...
Page 412: ...398 Figure 5 96 Figure 5 97...
