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Power supply balancing

greg long_4
Occasional Advisor

Power supply balancing

We use Proliant severs exclusivly in our datacenter and I was noticing when looking at the power distribution on the back orf our racks, that power was not balanced across the 2 sides of our racks. We use a pde on each side going to its own leg of power for redundancy but the power supplies from hp dont seem to ballance to load to each power supply. I have several questions


1) Is this normal?

2) is there a way to adjust this?

3) Is there a way to look at the amp load for each power supply ( i could not find this in the inisght web page for the servers) (i know blades list this)

4) are there any HP docs that better explain this behavior (have senior management asking me this)



Ralph Frampton
Frequent Advisor

Re: Power supply balancing

What you are observing may be dependent on the type of Proliant server(s) you have in use. I saw something related to your topic recently while working on some of our various models but don't remember exactly which type (eg. Proliant DL 360 or 380 G5 or Proliant DL 180 G6 series).


I found this HP info for a ProLiant DL360 G6 via a Google search (proliant power supply standby balanced):


It includes:


Added support for the Power Supply High Efficiency Mode feature which is configured in the Power Management Options in the ROM-Based Setup Utility (RBSU). This feature allows configuring how the system will handle redundant power supply configurations. High Efficiency Mode will provide the most power efficient operation with redundant power supplies by keeping one power supply in standby mode at lower power usage levels. Balanced Load will share the power delivery equally between both installed power supplies. This functionality requires the server to be upgraded to iLO 2 Firmware revision 1.77 or later.


Based on that, it looks like you'll need physical access to the server console or via ILO & a maintenance window to reboot & go into the RBSU to check/set the options providing you have the minimum version of ILO firmware revision in place. That description likely also explains why I can't find settings related to this via the server's SMH or ILO web access interfaces for  the couple I checked.


If I recall correctly, I believe we chose to run ours in the balanced mode.


For servers that have ILO2 or newer, you should be able to find information via the SMH or ILO web access interfaces that show you how much power the server is consuming. I don't recall seeing a break out of loading per power supply though... but the ILO power mgmt page will show the current, min/max for the last 24 hours (note: the 24 hour data is reset when you restart the server).

Ralph Frampton
Frequent Advisor

Re: Power supply balancing



By "show the current, min/max" - I meant power consumption in Watts. Example SMH Power report in SNMP mode for a DL 360 G5:

Current Power Reading:   270 Watts