Volume Relationship - D-Link DSN-6020 User Manual

RAID 6
RAID 0+1
RAID 10
RAID 30
RAID 50
RAID 60
JBOD
1.2.3

Volume relationship

The below graphic is the volume structure which D-LINK has designed. It describes the
relationship of RAID components. One RG (RAID group) consists of a set of VDs (Virtual
Disk) and owns one RAID level attribute. Each RG can be divided into several VDs. The
VDs in one RG share the same RAID level, but may have different volume capacity. All
VDs share the CV (Cache Volume) to execute the data transaction. LUN (Logical Unit
Number) is a unique identifier, in which users can access through SCSI commands.
LUN 1
VD 1
PD 1
2-dimensional parity protection over the member disks. RAID 6 needs
at least four hard drives.
Mirroring of the member RAID 0 volumes. RAID 0+1 needs at least
four hard drives.
Striping over the member RAID 1 volumes. RAID 10 needs at least
four hard drives.
Striping over the member RAID 3 volumes. RAID 30 needs at least six
hard drives.
Striping over the member RAID 5 volumes. RAID 50 needs at least six
hard drives.
Striping over the member RAID 6 volumes. RAID 60 needs at least
eight hard drives.
The abbreviation of "Just a Bunch Of Disks". JBOD needs at least
one hard drive.
LUN 2
VD 2
+
+
RG
PD 2 PD 3
LUN 3
Snapshot
VD
+
DS
Figure 1.2.3.1
11
Cache Volume
RAM