BladeSystem Virtual Connect
Showing results for 
Search instead for 
Did you mean: 

Virtual Connect (vc) thermal event

Trusted Contributor

Virtual Connect (vc) thermal event

Meg was looking to help a customer:




Has anyone ever experience a vc module complaining of a thermal event and not the servers?  I have a customer with multiple chassis and the VC flex-10 module (fw 4.2) is periodically throwing off a thermal event and failing over. 


I would think if it was hot enough for the interconnects to get snippy, the blades would too.  As far as I know all fans are installed and functions (they also don’t seem to running at full speed)




 The customer has a case open already and support wanted them to stabilize their datacenter environment first before proceeding (sounds like this particular facility has cooling issues)


I was just doing some research since I have never heard of thermal events on VC modules without everything else in the enclosure complaining.


I’ve already forwarded the case number to our team’s service manager to escalate if need be.




Lots of conversation:




Input from Dan:

2 things to know about Interconnect cooling in general.


1)      Interconnects get cool air from the small slits on the left and right side of the chassis.
This goes all the way back to the last 1 inch of the Interconnect where it comes in a small 1 inch long hole in the side of the module.
The airflow then goes back to front inside the Interconnect module and gets pulled into the air chamber near the Midplane, does a 180 and goes out through one of the Fans.

2)      There are no Flaps/doors, like the Blade Slots and Fan Slots have, on Interconnects.
Therefore you MUST make sure you don’t have any empty Interconnect bays during normal operation.
Either use the Interconnect Blank which covers that 1” slit in the side, or stick another module (any interconnect) into the slot and just don’t push it all the way in.




Reply from Kurt:

Thank you, Dan, for highlighting the cooling challenges for these I/O modules.  It is imperative for users to install blanks or modules into unused bays to keep the air from short circuiting the active modules in older enclosures. 


We actually incorporated a design change to the chassis just prior to the introduction of the Platinum c7000 enclosure last year that adds shut off flaps to the I/O bays.  These will impede the airflow and minimize the effects of the air short circuit.  However, we still recommend installing blanks or keeping modules in their bays until they are ready to be replaced.


From Dan:

Sweet, now I learned something new today too.


Kurt if you have any pictures or this is in a PDF somewhere so we in the field know how to check if a chassis has flappage or not, would be much appreciated.


Pictures from Jerry:

You should be able to tell by looking into an empty bay. Here are the pictures. First one from an older enclosure and the second one from a newer one.








Hope that helps. Any questions?