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

[Hank Nussbacher]

Oldish thread:

>Re: 7206VXR Big CPU Increase After 12.4 Upgrade
>
>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.

Mark,

We hit the same problem (CPU doubled - see graph from mid-Feb at - 
http://noc.ilan.net.il/stats/ILAN-CPU/tau-7206-cpu.html) going from 
12.4(4)T1 to 12.4(11)T1 so if you want try 12.4(4)T1  and your CPU should 
not rise.   We have an open TAC case on this issue for 3 weeks now.

-Hank Nussbacher
http://www.interall.co.il


>----- 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.
> >>