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) is connected with two HDDs, creating one Disk Group. Two RAID1
virtual disks (VD) are defined in the Disk Group.
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.
RAID Controller
VD0-1
50 GB
VD1-1
30 GB
HDD 1
(80 GB)
DG0 160 GB
VD0 (RAID1)
VD0-2
50 GB
50 GB
VD1-2
VD1 (RAID1)
30 GB
30 GB
HDD 2
(80 GB)
Configuring Your Server 4-29