PSU showing Power save and overall status : N/A

[anandrajt]

Hi,

In UCS chassis 5108,we noticed a 2 PSU was faulty to check properly  we swapped a cable and one of the PSU came up but another PSU was on same status. so we raised PSU and replaced it, but the overall status of the PSU was N/A and its not glowing green LED. Its blinking the Green LED but not continuous glow.

Please find the attached snap.

./Anandraj

[Marcus Xavier Gomes]

Hi Anandraj,

What´s your configuration on power groups and firmware version? N+1 or Grid?1.x or 2.x?

The Blinking green led and status power-save,  I belived this one is a standby.

When you configure N+1, two PSU work and one Standby mode then If you configure Grid all PSU work together and all Green LED  are glowing.

Follow below documantion with Power Group configuration:

http://www.cisco.com/en/US/docs/unified_computing/ucs/sw/gui/config/guide/141/UCSM_GUI_Configuration_Guide_141_chapter29.html#concept_B17F97D8074A4CB590309E3E8C8DD9F9

PS:

I found this information below, too.

The power supply is providing no power to the system but can be powered up

quickly in the event of another power supply failing. This mode saves power

in two ways:

1. It reduces the power consumption of the PSU, as there is no output the PSU

only requires a small amount of power to keep the capacitors charged and

circuitry active.

2. It increases the load on the remaining PSUs shifting them further on their

efficiency curves.

Kind Regards,

Marcus GOmes

[David Alpizar]

Please check on the following PDF that explains very well the power distribution on the UCS chassis.

The PSU will be placed as save mode according the amount of power needed on the chassis.

You can generate the chassis tech support and IOM and check on the powercli file to check the power budget required by the system according the amount of blades installed on the system.

Hope this help!

[anandrajt]

Hi,

Thanks for everyone support. The issue due to an bug

CSCub84671:

http://tools.cisco.com/squish/3a54A

CSCub84671 Bug Details

Equipment   Chassis Power Problem with No Hardware Errors/Status Change
Symptoms: Equipment Chassis Power Problem with fault being "Power state on chassis   X is redundancy-failed" Conditions: 5108 Chassis with 4 PSUs and n+1 power redundancy state. Workaround: Re-seat all power cables to the chassis in a downtime or Set power state redundancy to 'non-redundant' and change it back to n+1