HP hpe proliant dl20 gen9, User Manual, Page: 13 / 131

Component identification 13
System maintenance switch
Position Default Function
S1
Off Off = iLO 4 security is enabled.
On = iLO 4 security is disabled.
S2
Off Off = System configuration can be
changed.
On = System configuration is locked.
S3
Off Reserved
S4
Off Reserved
S5
Off Off = Power-on password is enabled.
On = Power-on password is disabled.
S6
Off Off = No function
On = ROM reads system
configuration as invalid.
S7
Off Off = Set default boot mode to UEFI.
On = Set default boot mode to legacy.
S8
— Reserved
S9
— Reserved
S10
— Reserved
S11
— Reserved
S12
— Reserved
To access the redundant ROM, set S1, S5, and S6 to on.
When system maintenance switch S6 is set to the On position, the system is prepared to erase all system
configuration settings from both CMOS and NVRAM.
IMPORTANT: Before using the S7 switch to change to Legacy BIOS Boot Mode, be sure the
HPE Dynamic Smart Array B140i Controller is disabled. Do not use the B140i controller when
the server is in Legacy BIOS Boot Mode.
NMI functionality
An NMI crash dump creates a crash dump log before resetting a system which is not responding.
Crash dump log analysis is an essential part of diagnosing reliability problems, such as failures of
operating systems, device drivers, and applications. Many crashes freeze a system, and the only
available action for administrators is to restart the system. Resetting the system erases any information
which could support problem analysis, but the NMI feature preserves that information by performing a
memory dump before a system reset.
To force the system to invoke the NMI handler and generate a crash dump log, do one of the following:
•
Use the iLO Virtual NMI feature.
•
Short the NMI header (" System board components " on page 11 ).
For more information, see the Hewlett Packard Enterprise website ( http://www.hpe.com/support/NMI ).
Drive numbering
The following images show the drive numbering for each of the supported drive configurations. For drive
box numbering information, see "Front panel components (on page 6 )."