Cisco 3750X-48P-L High CPU Utilization.

[Hitesh Parmar]

Hello Team,

We are facing high CPU Utilization on Cisco 3750X-48P-L without any traffic on it.

Please find the attached log files for 2 separate 3750's stack, we have upgraded the IOS of SW2 from "c3750e-universalk9-mz.122-55.SE3.bin" to

"c3750e-universalk9-mz.122-55.SE4.bin" but still we found the same issue with CPU utilization.

Thanks.

[nkarpysh]

Hi Hitesh,

CPU is spiking due to "HULC running con" process which is actually the "HULC running config" process. This process "wakes

up" once a configuration change has been made. Furthermore this process

forwards the configuration changes, which has been made further on the other

members of the stack.

Generating the running configuration is a quite CPU intensive process, so if

this is executed the CPU usage will be high.

The CPU load created by the "HULC running con" should normally only last as

long as it would take to perform a "sh run" of the configuration and then it

should become back dormant till another change has been done.

So I propose following action plan:

Check if the high CPU is always caused by the HULC running con process.

Check if there are any scripts/snmp making continuous changes to the

configuration:

E.G. you can search for smth like this in the logs

Last configuration change at 11:24:00 PST Thu Nov 15 2007 by admin

Please check the

High CPU During a Configuration Change

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_tech_note09186a00807213f5.shtml#topic4

Nik

[Hitesh Parmar]

Hi Nikolay,

Thanks for your response,

The CPU Utilization increases only when any configuration change has been made, the "hulc running con" spikes during this time only.

Apart from it the average CPU utilization is around 20-30%.

Hitesh.

[nkarpysh · Accepted solution]

Hi Hitesh,

In this case it is not a subject to worry about it. This docuent explaining that in details showing that is expected behaviour:

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_tech_note09186a00807213f5.shtml#topic4

Hope this helps,

Nik

[nkarpysh]

If you have a chance please close this thred selecting the right answer among all for it to be usefull for other later.

Thanks,

Nik