[c-nsp] 7206VXR Big CPU Increase After 12.4 Upgrade

[Mark Taylor]

For the benefit of the list and archives, we went back to 12.3.22 yesterday 
and our CPU levels dropped back to more like the previous levels.

The "%IF-4-BACKWARD_COUNTERS" have also disappeared since we went back to 
12.3.

Would recommend staying with 12.3 if you don't need a specific feature of 
12.4 as it is slightly more resource hungry (around 15 percent higher at 
just over 200Mbps in our experience).

Thanks to everyone for their assistance,
Mark.

----- Original Message ----- 
From: "Rodney Dunn" <rodunn at cisco.com>
To: "Mark Taylor" <maillist at smashie.ision.co.uk>
Cc: <cisco-nsp at puck.nether.net>
Sent: Tuesday, January 30, 2007 4:02 PM
Subject: Re: [c-nsp] 7206VXR Big CPU Increase After 12.4 Upgrade


> There are a lot of new features in the switching vectors between
> 12.3 and 12.4 so you will see an increase in CPU.
>
> In an upcoming 12.4(last)T release that will then be 12.5 mainline
> that is being changed so the net result will not be the same
> CPU impact as features are enabled that has traditionally been the
> case.
>
> Can you post your configuration minus any senstive information in it?
>
> Or unicast it to me...
>
> Rodney
>
> On Tue, Jan 30, 2007 at 02:01:39PM -0000, Mark Taylor wrote:
>> Hi,
>>
>> We upgraded one of our 7206VXR NPE-G1's from 12.3(12a) to 12.4(12) this
>> morning to cover the recent security releases. We decided to make the 
>> major
>> revision jump as we were reloading.
>>
>> After the reload the box jumped from 20 percent cpu to 35 percent on the 
>> new
>> 12.4(12) image and at the time there was around 75Mbps in each direction 
>> of
>> traffic running through the box - so an immediate increase of 15 percent.
>>
>> Now there is about 185Mbps each way and cpu is at 65 percent. This would
>> have been about 45 percent before the change of image, so an increase of 
>> 20
>> percent.
>>
>> This is looking very much like cpu could potentially increase more 
>> quickly
>> than traffic. The jump in cpu between images is beginning to concern me a
>> little. Has anybody else experienced this? Is it normal?
>>
>> The box is a peering router running IPv4 and OSPF, a full BGP table from 
>> one
>> upstream and about 20 other direct peers at a small IX and a few ACLs. 
>> CEF
>> is still running.
>>
>> I was hoping to get around 350Mbps through the box before running out of 
>> cpu
>> and it was looking that way based on 12.3(12a). I guess I could go back 
>> to
>> 12.3(22) which is fixed, assuming that the increase in cpu comes with 
>> 12.4.
>> I just wanted to find out if this big jump in cpu between releases was
>> normal/expected.
>>
>> Any help/experience appreciated.
>> Thanks,
>> Mark.
>>
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