HP ProLiant DL170e G6 Server - Manual (Page 39)

Power capping 39
To support the SL-APM power capping functionality, all tray nodes in the chassis must be rebooted after the
SL Chassis Firmware has been updated, (for s6500 chassis, the required version is v4.3 or higher) and the
appropriate BIOS version has been flashed. A reboot is also required anytime you add a LO100 Advanced
Pack, or iLO Scale Out, or iLO Advanced License to the node. Upgrading to future versions of SL Chassis
Firmware or SL-APM firmware does not require a reboot of the node to support the power capping feature.
Power capping and measurement tolerance
The average chassis power level displayed by SL-APM will not exceed 5% above the chassis power cap.
NOTE: The power baseline process is required for power capping functionality to work
properly. All servers must be powered on and running an expected typical workload before
starting the power baseline process. Because the baseline process will cap the servers briefly,
performance will be impacted while power is measured and the baseline established.
As with any measurement system, variations in temperature, input power, and system loads will impact the
accuracy of the power calculations. All power reading displayed by this utility will have a -/+ 5% tolerance.
However, meter errors can be both positive and negative, so guardband for meter tolerance, as a
percentage of the cap, can approach zero as the number of servers increases.
Invalidating a power baseline
Since power baselines are global, the SL-APM monitors the domains for changes in server and power supply
presence when a power baseline has been established. If a change occurs (for example, if a new server is
installed), then the SL-APM detects this change and invalidates the current power baseline. This invalidation
prevents any new caps from being set, but does not disable any existing caps that are set.
If a baseline has been invalidated due to changing hardware in the SL-APM domain, then several options are
available:
• If the change was caused by replacement of equipment (for example, a failed power supply was
removed and a new one inserted) then you could restore the old baseline by resetting the SL-APM and
forcing it to re-read and re-compare the existing power baseline from the resident EEPROM.
• Always use the SET POWER BASELINE command to establish a new power baseline when the domain
configuration changes because of one or more of the following changes:
o SL Power Management Controller (SL Chassis) Firmware has been updated.
o Add or remove the power supply.
o Install or uninstall a new server or enclosure.
o Add or remove memory from the tray.
o Add or remove CPU from the tray.
o Add or remove GPU from the tray.
Power capping licensing
All servers that are being power capped must have the iLO\LO100 advanced license installed. Before a
power baseline can be established, the SL-APM verifies that all the servers housed in an SL enclosure have the
advanced license pack installed. If any resident servers in the enclosure do not have the iLO\LO100