How to change Nexus 3172T airflow direction

[bhagen]

Like some others here, we bought two 3172t's but failed to check the airflow direction...and of course they came with the "wrong" direction.

We later ordered two more 3172T's for our DR site and made sure the airflow was the correct direction.

For reasons better left unsaid (too much typing would be needed!), we now need to swap the fans and power supplies from one set of switches to the other (so we can move one set to a different site).

I discovered that you can't hotswap fans if the airflow is different...with all 4 switches running, I started swapping fans between 2 of them, and both switches started displaying "invalid airflow direction detected; rebooting switch in 60 seconds". So I put them all back, but the switches rebooted a couple times anyway.

I'm at a loss finding documentation on how to swap them "correctly", even after looking thru the documentation.

So: has anybody done this, and/or does anybody have a link to directions? 

Thanks!

[balaji.bandi]

Yes that is the reason BoM very important and Cisco SE always usefull, before you placing order.

check this thread may help you :

https://community.cisco.com/t5/server-networking/nexus-3k-airflow-direction/td-p/3206214

[bhagen]

I should have mentioned that I already read that thread. It doesn't help, since I already have the fans and power supplies I need.

Wonder if I'm going to have to submit a case to TAC for this...

[balaji.bandi]

If you that information already, suggest to Open TAC case and take suggestions.

[Mark Malone]

You cant change it ,you need new fans there manafactured like that work differently happened us with 5ks before

[bhagen]

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@Mark Malone wrote:
You cant change it ,you need new fans there manafactured like that work differently happened us with 5ks before

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Right; I have the fans and power supplies that blow the "other" way. I attempted to hot-swap the fans, but got the “fan-direction mismatch, shutting down in 60 seconds” messages, so I had to swap them back.

I'm asking if there's a command or procedure I need in order to tell the switches that I'm putting the "other" fans in.

[balaji.bandi · Accepted solution]

I do not believe you have ability to do manual configuration, it automatically detect.

i only see the option here to change in maintenance window.

[Mark Malone]

it should auto detect i would TAC that but here is a command that may stop the alerting but wont fix the directional issue

no system shutdown fan-direction mismatch

[bhagen]

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@balaji.bandi wrote:

I do not believe you have ability to do manual configuration, it automatically detect.

i only see the option here to change in maintenance window.

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I just heard back from TAC. Indeed, the only way to reverse the fan direction is to shut down the switch and then swap fans and power supplies.

So  @balaji.bandi gets the prize for the correct answer! :-)

Thanks for all the replies!

[balaji.bandi]

Glad to hear that you have right answer, appreciate your feedback.