show tech and cpu load

amit bhatnagar · ‎12-27-2013

Hello

we have 2 6500 in VSS , with image 15.1(1)SY1.

I had to do show tech as there was some issue in our network , when i gave this command immidiately show process cpu output showed usage as 100% and resource was SSH Process and show tech output never got complete session got hanged and I had to open new VTY session

I want to know does this happen eveytime when we give show tech or there is a issue with our device .

Jon Marshall · ‎12-27-2013

Amit

It is not necessarily an issue with your switches. When you are logged in via the vty lines and you issue a command like "sh tech" there is a large amount of data to be displayed and it is normal for the CPU to spike when it does this -

Q. How can we reduce the process for SSH on 6500?

A. If it is virtual exec, that is used for servicing vty lines, Vty lines are used for logging into the switch. If we are trying to dump a huge output like "show tech", it is expected to see high CPU and is not a matter for concern.

full link -

https://supportforums.cisco.com/docs/DOC-22037

so what you are seeing is normal. But what is not normal is the display getting hung and having to open a new session.

So if it happens all the time it would be a problem but it could just be that at that particular time the switch was busy doing other things that also placed a load on the CPU.

Jon

amit bhatnagar · ‎12-27-2013

Thanks for reply Jon , its all the time only thing which i see in logs is below error which have started today only

Dec 27 12:49:52: %SNMP-SW1-3-INPUT_QFULL_ERR: Packet dropped due to input

queue full

And i see drops in show snmp as well , do i need to disable snmp or there is any other solution not sure if issues are related

Jon Marshall · ‎12-27-2013

Amit

It may not be the cause of the high CPU it may be a symptom. See this thread for more details -

https://supportforums.cisco.com/thread/2226204

what exactly are the networks problems you are seeing ?

Jon

amit bhatnagar · ‎12-27-2013

not any thing specific we were trying to get show tech for some old issue with ASA

thanks for ur help