combined and redundant mode for power supplies in 4500,6500

[sarahr202]

Hi every body!

I have few questions:

combined mode:

Let me quote from my cisco press book:

" If one power supply fails in combined mode, the switch powers down some of its modules until the required power load can be met by one functioning power supply."

How does switch determine which module's power be turned off first?

Redundant mode:

How can we determine which power supply is suppling power to modules in switch.Is it power supply #1 or #2?

thanks a lot!

[hakhan]

did u get answer

[sarahr202]

Excuse my ignorance.

My book did not specify that redundant mode is different for 4500 and 6500 switches. It just says 4500 and 6500 use up to 2 power supplies and they can be used in combined mode and redundant mode.

I had a clear understanding about redundant mode

redundant mode(4500): one power supply is powering the switch while the other is on back up.

Redundant mode(6500): both are

powering the switch , with each powering at 50 percent of its total capacity

I have one question about combined mode.

Is combined mode in 6500 switch same as combined mode in 4500 switch?

My book and links forwarded did

not address this question.

The link says(6500 switch)" In combined mode each supply is powering the switch at 83 percent of its total capacity"

Is it same for 4500 switch or combined mode is different in 4500 switch.

thanks a lot!

[Edison Ortiz]

Sarah,

The link in my first post contains all these information. Here is a section of that link:

When your switch is configured to combined mode, the total available power is not the mathematical sum of the individual power supplies. The power supplies have a predetermined current sharing ratio

HTH,

__

Edison.

[sarahr202]

Thanks a lot Edison and excuse my oversight.

I did find the all answers to my questions except for one.

How does switch determine which power supply is #1 and which power supply is number #2?

thanks a lot!

[Edison Ortiz · Accepted solution]

How about some graphical images? :)

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/hardware/Chassis_Installation/Cat6500/01over.html

HTH,

__

Edison.

[sarahr202]

Thanks a lot Edison for excellent link and great help!

[sarahr202]

Just a quick question.Let me quote from the link.

"If you have the power management mode set to redundant mode and only one power supply installed, your switch will accept the configuration but operates without redundancy."

I noticed that redundant power supply has specific slot in chassis.

How about if install the only one power supply where redundant power should be installed, Would switch operates?

thanks a lot!

[Edison Ortiz]

That's a good question, ideally when using one power supply, you should insert it on the PS1 slot.

__

Edison.

[sarahr202]

T hanks a lot Edison for your reply.

But if we don't install the power supply

in p1 slot but install it in p2 slot. would the switch work or generate an error message.

thanks !

[Edison Ortiz]

I don't know..

[sarahr202]

Thanks for your reply Edison!

[shamilton-wilkes]

Sorry to add to this thread after such a delay:

Just converted a pair of 6509's to VSS at the weekend, one of which doesn't quite have enough power for redundant mode - due to the power reservation for the Redundant Supervisor. But redundant supervisors aren't supported under VSS and won't be for a long time I expect.

Is there any way to remove the reservation?

[jcdod]

No, you can't remove the reservation. You can, however, run another module instead of a sup in that slot to recoup some of the waste.

[Ahmad-Maan]

i have a different issue in Power supply as mentioned below please suggest me way forward for fix-up i have checked physically switch power supply is found 3 green lights. 

Power                                             Fan      Inline

Supply  Model No          Type       Status       Sensor   Status

------  ----------------  ---------  -----------  -------  -------

PS1     none              --         --           --       --    

PS2     PWR-C45-4200ACV   AC 4200W   good         good     good  

PS2-1                         220V   good        

PS2-2                         220V   good        

Power supplies needed by system    : 1

Power supplies currently available : 1

[ItnfraInfo]

hi every one.

we have a similar case

a 4500 switch working in redundant mode.

when we have pulled one of the power supply the switch couldn't operate

what could be the issue?