Administrator Guide

also supported additional storage in the form of external expansion shelf enclosures (see the DR Series Expansion Shelf
section in this topic). The hot-swappable data drives that are attached to the RAID controller are configured as:
• 11 drives that operate as RAID 6, which act as virtual-disks for data storage (drives 1–11).
• The remaining drive (drive 0) acts as the dedicated hot-spare drive for RAID 6 for the system.
The DR Series system supports RAID 6, which allows the appliance to continue read and write requests to the RAID
array virtual disks even in the event of up to two concurrent disk failures, providing protection to your mission-critical
data. In this way, the system design supports double-data drive failure survivability.
If the system detects that one of the 11 virtual drives has failed, then the dedicated hot spare (drive slot 0) becomes an
active member of the RAID group. Data is then automatically copied to the hot spare as it acts as the replacement for
the failed drive. The dedicated hot spare remains inactive until it is called upon to replace a failed drive. This scenario is
usually encountered when a faulty data drive is replaced. The hot spare can act as replacement for both internal
mirrored drives and the RAID 6 drive arrays.
图 1: DR4000/DR4100 System Drive Slot Locations
Drive 0 (top) Drive 3 (top) Drive 6 (top) Drive 9 (top)
Drive 1 (middle) Drive 4 (middle) Drive 7 (middle) Drive 10 (middle)
Drive 2 (bottom) Drive 5 (bottom) Drive 8 (bottom) Drive 11 (bottom)
DR Series Expansion Shelf
Each DR Series system appliance supports the installation and connection of up to two Dell PowerVault MD1200 data
storage expansion shelf enclosures. Each expansion shelf contains 12 physical disks in an enclosure, which provides
additional data storage capacity for the basic DR Series system. The supported data storage expansion shelves can be
added in 1 Terabyte (TB), 2 TB, or 3 TB hard drive capacities.
The physical disks in each expansion shelf are required to be Dell-certified Serial Attached SCSI (SAS) drives, and the
physical drives in the expansion shelf uses slots 1–11 configured as RAID 6, with slot 0 being a global hot spare (GHS).
When being configured, the first expansion shelf is identified as Enclosure 1 (in the case where two enclosures are
added, these would be Enclosure 1 and Enclosure 2). Adding an expansion shelf to support the DR Series system
requires a license. For more information, see Expansion Shelf Licenses. For more general information about the
supported storage enclosures, see support.dell.com/manuals.
注: The 300 Gigabyte (GB) drive capacity (2.7 TB) version of the DR Series system does not support the addition of
expansion shelf enclosures.
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