6500: power-redundancy mode combined & Power fail

[florian.pipper]

Hi,

I have a 6500 chassis with 2 power supplies. At the moment  I am using the default configuration:

power-redudancy mode redundant

The problem is that an inserted module is in "power deny" state due too insufficient power.

I know, that It's not a good idea to change into combined mode (loss of redundancy), but my customers requested this anyway.

So I will change to combined mode. So here's the 1 million dollar question:

"Which modules will go into power deny, if one of my power supplies fails?"

The 6500 config guide states:

"Power supply is removed with
redundancy disabled
• System log and syslog messages are generated.
• System power is decreased to the power capability of one supply.
• If there is not enough power for all previously powered-up modules, some modules
are powered down and marked as power-deny in the show power oper state field."

Well, do you know if there's any way to configure some kind of priority?

E.g. I definetly don't want by 10Gig Module or WiSM module to be in power deny.

Can i statically make sure, those module will be powered on for sure?

Like: "power enable module slot_number"

How is this calculated? Or is random?

Any experiences to share?

Thanks for your help,

Regards

Florian

[andtoth · Accepted solution]

Hi,

I hope the following helps.

2.10 Power Shutdown Sequence
The previous section highlighted the recommendation for running in redundant mode. Should there be a requirement to run in combined mode, an extra precaution needs to be taken. In the event of a failing power supply that leaves the system without enough power to
drive the total configuration, inline devices and line cards will be shut down by the power management software to fall within operating power capabilities.
In order for the user to recognize the event and its consequences, the shutdown sequence logic should be known and understood: in particular, the Catalyst 6500 control software will first start to power down inline devices from the highest numbered port to the lowest numbered port, then from the bottom slot up. If after powering down all inline devices there is still insufficient power, the system will start to power down line cards from the bottom slot up with the exception of the supervisor module and of the services modules (that is, firewall module, VPN module, IDS module, and so on). Supervisor and services modules are the last modules left operating. For this reason, important hosts should be plugged into ports on the top-most modules (that is, slots 1, 2, 3, and so on) and from the lower numbered ports up. It is worth noting that the order of shutdown is fixed by the system and cannot be changed.

From: http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd805457cc.html

Best regards,

Andras

[florian.pipper]

Thanks. Exactly, what I was looking for.

[Vinayaka Raman]

Will switching the power redundancy mode from "redundancy" to "combined" cause any outage.? I have cat 6509 chassis currently running on redundancy mode "redundancy"..there are six POE modules and all ports equipped. the remaining inline wattage is 4W and I wanted to increase this.