NEC NF1500-SR40E, User Manual

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xxvi
Hot Spare Feature
Spare disks can be installed in the disk array unit. If a disk drive becomes defective, the data in the
defective disk drive is recovered in the spare disk. After the data recovery, the disk drive operates
normally if another disk drive becomes defective.
A defective disk drive can be replaced without turning off the power of the disk array unit.
With the shipping default, if the spare disk replaces a disk drive that has become defective and the
spare is replaced with a new drive, the replacement disk drive works as a spare disk drive.
The data can also be recovered in another other disk enclosure.
Example of hot spare operation (LDN0 RAID5)
PDN14 Spare disk PDN14 PDN14
PDN13 PDN13 PDN13
PDN12 PDN12 PDN12
PDN11 PDN11 PDN11
PDN10 PDN10 PDN10
PDN9 PDN9 PDN9
PDN8
⇒
PDN8
⇒
PDN8
PDN7 PDN7 PDN7
PDN6 PDN6 PDN6
PDN5 PDN5 PDN5
PDN4 PDN4 PDN4
PDN3 PDN3 PDN3
PDN2
LDN0 RAID5
PDN2
LDN0 RAID5
PDN2
LDN0 RAID5
Spare Disk
PDN1 PDN1 PDN1
⇐
PDN0 PDN0 PDN0
Failure in PDN1 Recovery of data
in spare disk Replacement of PDN 1
PDN1 works as a spare disk
* PDN: Physical Disk Number
LDN: Logical Disk Number
Do not move any of the factory-installed disk drives into another slot.
The spare disk can operate only when it has a capacity and a revolution
equal to the defected disk drive.
If disk drives having different capacities and/or revolutions coexist, spare
disks of the different capacities and/or revolutions must be defined to manage
the disk drives clearly.
Up to 32 spare disks may be installed in the entire disk array unit.