Hardware options installation 116
that is degrading. This allows DIMMs that have a higher probability of receiving an uncorrectable
memory error (which would result in system downtime) to be removed from operation.
•
Mirrored memory—Provides maximum protection against failed DIMMs. Uncorrectable errors in one
channel are corrected by the mirror channel.
Advanced Memory Protection options are configured in the BIOS/Platform Configuration (RBSU). If the
requested AMP mode is not supported by the installed DIMM configuration, the server boots in Advanced
ECC mode. For more information, see the
HPE UEFI System Utilities User Guide for HPE ProLiant Gen9
Servers
on the Hewlett Packard Enterprise website (
http://www.hpe.com/info/ProLiantUEFI/docs
Advanced ECC memory configuration
Advanced ECC memory is the default memory protection mode for this server. Standard ECC can correct
single-bit memory errors and detect multi-bit memory errors. When multi-bit errors are detected using
Standard ECC, the error is signaled to the server and causes the server to halt.
Advanced ECC protects the server against some multi-bit memory errors. Advanced ECC can correct
both single-bit memory errors and 4-bit memory errors if all failed bits are on the same DRAM device on
the DIMM.
Advanced ECC provides additional protection over Standard ECC because it is possible to correct certain
memory errors that would otherwise be uncorrected and result in a server failure. Using HPE Advanced
Memory Error Detection technology, the server provides notification when a DIMM is degrading and has a
higher probability of uncorrectable memory error.
Online Spare memory configuration
Online spare memory provides protection against degraded DIMMs by reducing the likelihood of
uncorrected memory errors. This protection is available without any operating system support.
Online spare memory protection dedicates one rank of each memory channel for use as spare memory.
The remaining ranks are available for OS and application use. If correctable memory errors occur at a rate
higher than a specific threshold on any of the non-spare ranks, the server automatically copies the
memory contents of the degraded rank to the online spare rank. The server then deactivates the failing
rank and automatically switches over to the online spare rank.
Mirrored memory configuration
Mirroring provides protection against uncorrected memory errors that would otherwise result in server
downtime. Mirroring is performed at the channel level to one memory channel pair that can be either:
•
Channel 1 data being mirrored in channel 2
•
Channel 3 data being mirrored in channel 4
If an uncorrectable error is detected in the active memory channel, data is retrieved from the mirror
channel. This channel becomes the new active channel, and the system disables the channel with the
failed DIMM.
General DIMM slot population guidelines
Observe the following guidelines for all AMP modes:
•
Install DIMMs that are optimized for the installed processor.
To identify the processor type installed in the server, use the BIOS/Platform Configuration (RBSU) of
the UEFI System Utilities ("
Identifying the processor type
•
Install DIMMs only if the corresponding processor is installed.
•
Do not mix LRDIMMs and RDIMMs.
