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About the Hard Disk Drives
Images from cameras will be recorded on the built-in hard disk drive of this unit.
This unit manages recorded images by dividing the hard disk drive into 4 areas virtually.
• Normal recording area: Images recorded by manual recording will be stored in this area.
• Event recording area: Recording area for event recording
• Copy area: Copied images will be stored in this area.
• Pre-recording area: Images recorded by pre-event recording will be stored in this area.
It is possible to check the available disk space of each recording area on the "Disk Information" menu
("Maintenance" - "Disk Information").
(page 83)
The settings relating to the hard disk drives such as initialization of the hard disk drives of this unit or the extension
unit can be performed with the "HDD DISK MENU".
(page 90)
Note:
It is necessary to create either of a normal recording area or an even recording area. When a normal recording
area is not created, images recorded by manual recording and schedule recording will be stored in the event
recording area. When an event recording area is not created, images recorded by event recording and emer-
gency recording will be stored in the normal recording area.
Summary of the RAID 5 function (Redundant Arrays for
Independent Disks, independent data disks with distributed
parity blocks)
It is possible to use the RAID 5 function with the optional RAID board (WJ-NDB301).
RAID level 5 regards 3 or more drives as one drive, and it is possible to read data by attaching error correction data
even though one of the drives is broken automatically. (It is impossible to recover data if two drives are simultane-
ously damaged or the second drive data fails during the data recovery process.)
When using the RAID function, the logical disk size of the extension unit will be as below.
Logical disk size = Smallest size of the disk among the disks in the extension unit x (Number of the disks in the
extension unit – 1)
Note:
Depending on the model of a hard disk drive, the logical disk size may be a few percent smaller than the size
resulting from the formula above.
Important:
• It is impossible to use the RAID function with the WJ-ND300A alone if the WJ-ND300A in use is not featured the
built-in RAID board.
• The settings relating to the RAID function can be performed on the setup menu displayed on the LCD on the
front panel of the unit.
Refer to the Installation Guide for further information.
• It is impossible to format the pre-event recording area using the WJ-ND300A featured the built-in RAID board
alone. To perform the settings for the pre-event recording with the RAID function, it is necessary to use with an
extension unit. Refer to the operating instructions of the extension unit for how to configure the settings for the
RAID 5 function to be used on the extension unit.