126Manage hard disk drivesAbout hard disk drivesImages from cameras will be recorded on the HDD unit(s) in the recorder.This recorder manages the hard disk drives by dividing them virtually into the following recording areas.• Normal recording area: Recording area used when an event does not occur (Manual recording, schedule recording)• Event recording area: Recording area used when an event occurs (Post-event recording, emergency recording).• Pre-event recording area: Recording area used to record images before an event occursIt is possible to assign only one recording area to a hard disk drive.The settings of each recording area can be configured on the disk configuration page. (+ Page 127)Remaining capacities of each recording area can be checked on the disk configuration page or the "Maintenance" page - the"Disk information" tab. (+ Page 119)About the RAID 5/RAID 6 modeThe RAID 5/RAID 6 mode becomes available when optional RAID boards (WJ-HDB601) are installed in the recorder and exten-sion units.When the RAID5/RAID mode is applied, 3 or more hard disk drives are regarded logically as a single drive. Even if a troubleoccurs in one of the hard disk drives, the data on the faulty HDD can be recovered based on the error correction data automati-cally recorded on the other drives.The RAID 5 mode has an error correction data that recovers data when a single hard disk drive becomes faulty. The RAID 6mode has two error correction data that recovers data from other disk drives when two drives become faulty at the same time.• Logical disk capacity in the RAID 5 modeLogical disk capacity = Capacity of the smallest hard disk drive among the unit x (Total number of the hard disk drives in therecorder 1)• Logical disk capacity in the RAID 6 modeLogical disk capacity = Capacity of the smallest hard disk drive among the unit x (Total number of the hard disk drives in therecorder 2)* Depending on the models of hard disk drives installed in the recorder, the capacity may be a few percent smaller.Important:• To enable the RAID 5 mode, it is necessary to install 3 or more hard disk drives in the recorder. To enable the RAID 6 mode, itis necessary to install 4 or more hard disk drives in the recorder.• When an optional RAID board (WJ-HDB601) is not installed in the recorder, it is impossible to enable the RAID 5/RAID 6mode using the recorder alone.• The RAID 5/RAID 6 mode is determined using the [RAID] switch behind the front cover of the recorder. (+ Page 20)• Refer to the operating instructions of extension units for further information about how to determine the RAID 5/RAID 6mode.Determine the operation modeThe RAID 5/RAID 6 mode is determined using the [RAID] switch (+ page 20) behind the front cover of the recorder.Refer to page 54 for how to determine the operation mode.
