redundancy policy PSU

dell r630

from the documentation:

Your system supports the hot spare feature that significantly reduces the power overhead associated with power supply unit (PSU) redundancy.

When the hot spare feature is enabled, one of the redundant PSUs is switched to the sleep state. The active PSU supports 100 percent of the load, thus operating at higher efficiency. The PSU in the sleep state monitors output voltage of the active PSU. If the output voltage of the active PSU drops, the PSU in the sleep state returns to an active output state.

If having both PSUs active is more efficient than having one PSU in the sleep state, the active PSU can also activate the sleeping PSU.

The default PSU settings are as follows:
If the load on the active PSU is more than 50 percent, then the redundant PSU is switched to the active state.
If the load on the active PSU falls below 20 percent, then the redundant PSU is switched to the sleep state.

and also

When two identical PSUs are installed, power supply redundancy (1+1 – with redundancy or 2+0 – without redundancy) is configured in system BIOS. In redundant mode, power is supplied to the system equally from both PSUs when Hot Spare is disabled. When Hot Spare is enabled, one of the PSUs will be put into standby when system utilization is low to maximize efficiency.  

I hope this helps

Thanks

Hello,

each server model is different, which server are you referring to?

Thanks

how about not redundant and hotspare disable ? both psu are present and connected

In the no redundancy policy if there is sufficient PSU capacity (even with one PSU only) the system will continue to operate if there are any PSU failure. However no fault will be raised.

I still dont get it. It seems by what you wrote here that the "Redundancy policy" is completely ignored if the "hot spare" option is set to enabled. Is that it?

Right now I have 2 identical PSUs and hot spare enabled (primary PSU is PSU1). What changes in the system under these configs if I set "Redundancy Policy" from "not redundant" to "input power redundant"?

Do you know how much of electricity the system takes ups? As long as only 1 PSU can handle it, you could change the setting.

https://www.dell.com/support/manuals/en-us/idrac9-lifecycle-controller-v3.0-series/idrac_3.00.00.00_ug/configuring-power-supply-options?guid=guid-8f12589b-c8a1-427b-b356-e20b49f9652e&lang=en-us

so what is the best power configuration in this case?

redundant policy : ?

hot spare : ?

Hello, when setting in redundant the server can keep running if one PSU stops working. But if both PSUs stop working, the server will turn off. A hot spare is a feature that makes redundant PSUs switch off based on the server load. This makes remaining PSUs work harder and more efficiently if PSUs can support quickly switch. As I can see you have two PSUs and you are using them redundantly. If you want to save energy, you can turn on hot spare so that one of PSUs will go to sleep when the server isn't busy. 

Hello All,

I'm trying to get the information about power redundancy with snmp. I have several r930 and r940 servers with iDRAC 8 and iDRAC9. Please advice the correct command? I tied to use this one but it did not work:

snmpwalk -v2c -c <community_string> <iDRAC_IP> .1.3.6.1.4.1.674.10892.5.4.600.12.1.10

@DELL-Chris H ​,

Thanks for your reply.

Unfortunately, that did not work. For both, r930 and r940 I received the following output:

SNMPv2-SMI::enterprises.674.10892.5.4.600.10.1.1.5 = No Such Instance currently exists at this OID

Hello, could we go over this guideline once again? https://dell.to/41u9Bpi

Respectfully,