Users Guide

Table Of Contents
Managing Enclosures or Backplanes
You can perform the following for enclosures or backplanes:
View properties
Configure universal mode or split mode
View slot information (universal or shared)
Set SGPIO mode
Related concepts
Summary of Supported Features for Storage Devices on page 182
Supported Enclosures on page 181
Configuring Backplane Mode on page 201
Viewing Universal Slots on page 203
Setting SGPIO Mode on page 203
Configuring Backplane Mode
The 13th generation Dell PowerEdge servers supports a new internal storage topology, where two storage controllers (PERCs)
can be connected to a set of internal drives through a single expander. This configuration is used for high performance mode
with no failover or High Availability (HA) functionality. The expander splits the internal drive array between the two storage
controllers. In this mode, virtual disk creation only displays the drives connected to a particular controller. There are no licensing
requirements for this feature. This feature is supported only on a few systems.
Backplane supports two modes:
Unified mode The primary PERC controller has access to all the drives connected to the backplane even if a second
PERC controller is installed.
Split mode One controller has access to the first 12 drives and the second controller has access to the last 12 drives. This
splitting is not configurable. The drives connected to the first controller are numbered 0-11 while the drives connected to the
second controller are numbered 12-23.
By default, it is in unified mode.
iDRAC allows the split mode setting if the expander has the capability to support the configuration. You may want to enable this
mode prior to installing the second controller. iDRAC performs a check for expander capability prior to allowing this mode to be
configured and does not check whether the second PERC controller is present.
To modify the setting, you must have Server Control privilege.
If any other RAID operations are in pending state or any RAID job is scheduled, you cannot change the backplane mode.
Similarly, if this setting is pending, you cannot schedule other RAID jobs.
NOTE:
Warning messages are displayed when the setting is being changed as there is a possibility of data loss.
LC Wipe or iDRAC reset operation does not change the expander setting for this mode.
This operation is supported only in real-time and not staged.
Any change in this setting only takes effect after a system power reset. If you change from Split mode to Unified, an error
message is displayed on the next boot as the second controller does not see any drives. Also, the first controller will see a
foreign configuration. If you ignore the error, the existing virtual disks are lost.
Configuring Backplane Mode Using Web Interface
To configure backplane mode using iDRAC Web interface:
1. In the iDRAC Web interface, go to Overview > Storage > Enclosures > Setup
The Enclosure Setup page is displayed.
2. From the Controller drop-down menu, select the controller to configure its associated enclosures.
3. In the Value column, select the required mode for the required backplane or enclosure:
Unified
Split
Managing Storage Devices
201