NEC N8100-1422F, User Manual

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4-24 Configuring Your Server
Virtual Disk
Virtual disk is a logical drive defined in disk group. It is recognized as a physical drive by OS. The
allowable number of virtual disks is up to 16 per disk group, or up to 64 per controller.
The figure below shows a sample configuration in which the Onboard RAID Controller (LSI
Embedded MegaRAID) or Internal RAID Controller (N8103-116 equivalent) is connected with
three HDDs, creating one Disk Group. Two RAID5 virtual disks (VD) are defined in the Disk
Group.
HDD 1
(36 GB)
HDD 2
(36 GB)
HDD 3
(36 GB)
RAID Controller
DG0 108 GB
VD1-3
16 GB VD1-2
16 GB VD1-1
16 GB
VD0-1
20GB
VD0-2
20GB
VD0-3
20GB
VD0 (RAID5)
40 GB
VD1 (RAID5)
32 GB
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.
Hot-Swap
The hot-swap enables a HDD to be removed (or replaced) under system operation.
Hot-Spare
The hot-spare is prepared as an auxiliary HDD substituting for a defected HDD included in a logical
drive which is configured at a redundant RAID level. Detecting a HDD fault, the system
disconnects the HDD (or makes it offline) and starts rebuild using the hot-spare.