Logical Drive; Parity; Hot-Swap - NEC Promise SuperTrak EX8350 User Manual

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1-3. Logical Drive

A logical drive is configured with a group of more than one HDD. It is recognized as a physical drive by OS.
Up to eight logical drives are permitted by the card when four HDDs are installed in the server.
The figure below shows a sample configuration in which the disk array controller is connected with four
HDDs, three of which create a logical drive and the remaining HDD is set to a single hot-spare disk.
Disk array controller
Channel 1
(Port 1)
Channel 3
(Port 3)

1-4. Parity

The parity means redundant data. A single set of redundant data is created from the data saved in more than
one HDD.
The created redundant data is used for data recovery when a HDD is defected.

1-5. Hot-Swap

The hot-swap enables a HDD to be removed (replaced) under system operation.
For the hot-swap with the card, an additional HDD cage must be connected
to the card.
Check
Channel 2
(Port 2)
Channel 4
(Port 4)
Logical drive 1
LD 1-1
LD 1-2
LD x-x : HDDs assigned to
LD 1-3
Spare :
Spare
logical drive
Hot-spare disk