Users Guide

● 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 195
Supported enclosures on page 195
Configuring backplane mode on page 218
Viewing universal slots on page 220
Setting SGPIO mode on page 221
Configuring backplane mode
The Dell 13
th
generation 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 the following modes:
● Unified mode —This is the default 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. The
drives connected to the first controller are numbered 0-11 while the drives connected to the second controller are numbered
12-23.
● Split mode 4:20 — One controller has access to the first 4 drives and the second controller has access to the last 20 drives.
The drives connected to the first controller are numbered 0-3 while the drives connected to the second controller are
numbered 4-23.
● Split mode 8:16 — One controller has access to the first 8 drives and the second controller has access to the last 16 drives.
The drives connected to the first controller are numbered 0-7 while the drives connected to the second controller are
numbered 8-23.
● Split mode 16:8 — One controller has access to the first 16 drives and the second controller has access to the last 8 drives.
The drives connected to the first controller are numbered 0-15 while the drives connected to the second controller are
numbered 16-23.
● Split mode 20:4 — One controller has access to the first 20 drives and the second controller has access to the last 4 drives.
The drives connected to the first controller are numbered 0-19 while the drives connected to the second controller are
numbered 20-23.
● Information Not Available — Controller information is not available.
iDRAC allows the split mode setting if the expander has the capability to support the configuration. Ensure that you 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 operations do not change the expander setting for this mode.
● This operation is supported only in real-time and not staged.
● You can change the backplane configuration multiple times.
● The backplane splitting operation can cause data loss or foreign configuration if the drive association changes from one
controller to another controller.
● During the backplane splitting operation, the RAID configuration may be impacted depending on the drive association.
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.
218
Managing storage devices