OS Tuning
Drive Write Cache
The Drive Write Cache is an option that can be enabled or disabled in the HP Array Configuration Utility, CLI version. The default value for the Drive Write Cache is set to Disabled, and in order to change this the HP Arracy Configuration Utility, CLI version needs to be installed. When the Drive Write Cache option is enabled on a HP Smart Arrary Controller in a system, it can allow the HP Smart Array Controller to help make drive writes more efficient.
Accelerator Ratio
The Accelerator Ratio is an option that can be set to different percentages (in 25% increments) in the HP Array Configuration Utility, CLI version. The default value for the Accelerator Ratio is set to 0% Read and 100% Write. In order to change this the HP Arracy Configuration Utility, CLI version needs to be installed. Changing the Accelerator Ratio allows the array installed on the HP Smart Arrary Controller to adjust how it priotizes reads and writes.
ulimit -s [n | unlimited] (Linux)
Sets the stack size to n kbytes, or unlimited to allow the stack size to grow without limit.
vm.max_map_count-n (Linux)
The maximum number of memory map areas a process may have. Memory map areas are used as a side-effect of calling malloc, directly by mmap and mprotect, and also when loading shared libraries.
Zone Reclaim:
Zone reclaim allows the reclaiming of pages from a zone if the number of free pages falls below a watermark even if other zones still have enough pages available. Reclaiming a page can be more beneficial than taking the performance penalties that are associated with allocating a page on a remote zone, especially for NUMA machines.
Disabled unused Linux services via stop_services.sh script.
The following unused Linux services were disabled before the run in simple shell scirpt via the command "service {name} stop": abrt-ccpp, abrt-oops, abrtd, acpid, atd, auditd, autofs, avahi-daemon, cgconfig, cpuspeed, crond, cups, haldaemon, irqbalance, kdump, libvirt-guests, mcelogd, mdmonitor, messagebus, portreserve, postfix, rhnsd, rhsmcertd, rpcbind, rpcgssd, rpcidmapd, certmonger, lvm2-monitor, netfs, and sysstat.
Firmware Settings
One or more of the following settings may have been set. If so, the "Platform Notes" section of the report will say so; and you can read below to find out more about what these settings mean.
Intel Hyperthreading Options (Default = Enabled):
This feature allows enabling/disabling of logical processor cores on processors supporting Intel's Hyperthreading Technology. When enabled, each physical processor core operates as two logical processor cores. When disabled, each physical core operates as only one logical processor core. Enabling this option can improve overall performance for applications that benefit from a higher processor core count.
HP Power Profile (Default = Balanced Power and Performance):
Values for this BIOS setting can be:
HP Power Regulator (Default = HP Dynamic Power Savings Mode)
This option can only be configured if the HP Power Profile is set to Custom. Values for this BIOS setting can be:
Minimum Processor Idle Power Core C-State (Default = C6 State):
This option can only be configured if the HP Power Profile is set to Custom. This feature selects the processor's lowest idle core power state (C-state) that the operating system uses. The higher the C-state, the lower the power usage of that idle state (C6 is the lowest power idle state supported by the processor). Values for this setting can be:
Minimum Processor Idle Power Package State (Default = Package C6(retention) State):
This option can only be configured if the HP Power Profile is set to Custom. This feature selects the processor's lowest idle package power state (C-state) which is enabled. The proecessor will automatically transition into the package C-states based on the Core C-states, in which cores on the processor have transitioned. The higher the package C-state, the lower the power usage of that idle package state (Package C6(retention) is the lowed power idle package state supported by the processor). Values for this setting can be:
Energy/Performance Bias (Default = Balanced Performance):
This option can only be configured if the HP Power Profile is set to Custom. This option configures several processor subsystems to optimize the processor's performance and power usage. Values for this BIOS setting can be:
Collaborative Power Control (Default = Enabled):
This BIOS option allows the enabling/disabling of the Processor Clocking Control (PCC) Interface, for operating systems which support this feature. Enabling this option allows the Operating System to request processor frequency changes even when the server has the Power Regulator option configured for Dynamic Power Savings Mode.
For Operating Systems that do not support the PCC Interface or when the Power Regulator Mode is not configured for Dynamic Power Savings Mode, his option has no impact on system operation.
QPI Snoop Configuration (Default = Home Snoop):
This option allows the user to choose the snoop mode used by the processor and QPI bus. Changing this option can have an impact on memory performance. Values for this BIOS setting can be:
Thermal Configuration (Default = Optimal Cooling):
This feature allows the user to select the fan cooling solution for the system. Values for this BIOS option can be:
Processor Power and Utilization Monitoring (Default = Enabled):
This BIOS option allows the enabling/disabling of iLo Processor State Mode Switching and Insight Power Management Processor Utilization Monitoring.
When set to disabled, the system will also set the HP Power Regulator mode to HP Static High Performance mode and the HP Power Profile mode to Custom. This option may be useful in some environments that require absolute minimum latency.
Memory Patrol Scrubbing (Default = Enabled):
This BIOS option allows the enabling/disabling of Memory Periodic Patrol Scrubber. The Memory Periodic Patrol Scrubber corrects memory soft errors so that, over the length of the system runtime, the risk of producing multi-bit and uncorrectable errors is reduced.
Memory Refresh Rate (Default = 2x Refresh):
This BIOS option controls the refresh rate of the memory controller and may affect the performance and resiliency of the servers memory.
When set to 1x Refresh, the memory refresh rate will be decreased, the HP Power Regulator mode will be set to HP Static High Performance mode, and the HP Power Profile mode to Custom. This option may be useful in some environments that require absolute minimum latency.
When set to 3x Refresh, the memory refresh rate will be increased, the HP Power Regulator mode will be set to HP Static High Performance mode, and the HP Power Profile mode to Custom.
Last updated September 24th, 2014.