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c7000 behaviour if power supply fails

Trusted Contributor

c7000 behaviour if power supply fails

Sally and Nelson needed some help on how to answer a customer question:



Hi, Team,


Could someone help to suggest on this?  What's the shut down sequence in case of C7000 power supply failure? Thanks!

For c7000 enclosure with BL460c G6 servers, assume the servers require total max. 6000W, but currently real time running requires 3000W only.  What will happen if some power supplies fail and only two 2400W power supplies remain working.   Will the enclosure


- keep servers running (as the real time power requirement is 3000W only)?

- shutdown some servers

- shutdown all servers



Monty provided some great insite:


The c-Class Onboard Administrator does not automatically power off any server blade - for any reason.


The c-Class power subsystem design is a single power domain - with the total load shared by all power supplies that are active.  If enclosure Dynamic Power Savings is enabled – an enclosure power micro is performing real-time control of all the power supplies to ensure optimum power efficiency and protect against power supply failures from causing an enclosure power outage.


So in the scenario below, with the total load of 3000W and two 2400W power supplies remaining – those two supplies can provide up to 4800W of output power, so no servers will brown-out in this scenario.


If the total load in this scenario increases above the combined max output power of all power supplies - one or more servers or the entire enclosure may brown-out.


Multiple power supply failures is highly unlikely.  Having an AC input failure on one 'side' in the case of 100% redundant AC inputs would result in all power supplies on one 'side' being unable to share the enclosure load.  For this type of fault tolerance, the OA Power Mode should be configured for AC Redundant - which results in the OA only allocating up to the max output of half of the power supplies - to protect against a failure of all AC inputs on one 'side'.



Any other comments? Good info from Monty. Have you had power supply issues? Please let us know.