Bull Cedoc NovaScale R440 E2, User Manual, Page: 119 / 552

Configuring Your Server 4-25
Virtual Disk
A virtual disk is a logical drive defined in a disk group. It is recognized as a physical drive by the operating system. 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.
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 the system is running.
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. When detecting a faulty HDD , the system disconnects the HDD (or makes it offline) and starts
rebuild using the hot-spare.