Proware EP-4604D-G1S3, User Manual

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iSCSI GbE to SAS/SATA RAID Subsystem
User Manual 17
1.4 Volume Relationship Diagram
This is the design of volume structure of the iSCSI RAID subsystem. It describes the
relationship of RAID components. One RG (RAID Group) is composed of several PDs
(Physical Disks). One RG owns one RAID level attribute. Each RG can be divided into
several VDs (Virtual Disks). The VDs in one RG share the same RAID level, but may have
different volume capacity. Each VD will be associated with the Global Cache Volume to
execute the data transaction. LUN (Logical Unit Number) is a unique identifier, in which
users can access through SCSI commands.