NEC Express5800 120Rj-2 User Manual page 85

User Guide
The figure below shows a sample Configuration. The three HDDs are connected to the
Onboard RAID Controller (LSI Embedded MegaRAID) or Internal RAID Controller,
creating one disk group (DG).
Virtual Disk
Virtual disk is a virtual 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 is connected with
three HDDs, creating one Disk Group. Two RAID5 virtual disks (VD) are defined in
the Disk Group.
VD0-1
20GB
VD1-1
16 GB
HDD 1
(36 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 defective.
RAID Controller
HDD 1 HDD 2
(36 GB) (36 GB)
Figure 29: Sample RAID Configuration
RAID Controller
VD0-2
20GB
VD1-2
16 GB
HDD 2
(36 GB)
Figure 30: Sample Virtual Disk Configuration
Disk Group 0: 108 GB
HDD 3
(36 GB)
VD0 (RAID5)
VD0-3
40 GB
20GB
VD1-3
VD1 (RAID5)
16 GB
32 GB
HDD 3
(36 GB)
85
www.nec-computers.com
DG0 108 GB