Nexus 7706 3KW power modes

[startx001]

Hi,

I have 7706 chassis with 4 x 3KW power supply.

Right now mode is  PS-Redundant, and if two ps fails i have problem.

I want to switch to Combined mode but can i do that without interrupts and what will happen in Combined mode if two ps fail.

Combined mode

This mode allocates the combined power of all power supplies to active power for switch operations. "This mode does not allocate reserve power for power redundancy in case of power outages or power supply failures" - this worry me, what it exactly means?

Regards,

VZ

[Remi Astruc]

Hi @startx001 ,

In PS-Redundant, 1 PS is kept unused to takeover in case one of the active fails.

It means you currently have 9KW available and 3KW reserve. If 2 PS fail, 3KW is saved by the reserve and 3KW is lost, leaving you with 6KW active.

In Combine mode, all PS are bound into the available power and no PS is kept unused, meaning you'll have 12KW in nominal, and each PS failure (even the first one) decreases the available power. If 2 PS fail, 6KW is lost, leaving you with 6KW active...

Long story short, if you cannot live with 6KW, none of the settings will save you.

By the way, changing the setting should be non-disruptive, but doing in a maintenance window is recommended.

Remi Astruc