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2923 Views 3 Replies Latest reply: Aug 22, 2011 1:26 AM by James RSS

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High CPU Utilization on 3845 router

Aug 18, 2011 2:43 AM

HI ,

 

 

One of the router is showing above 50% utilization but when I checked Process CPU shorted ...only 1 process is taking more then 1% of cpu and other process are taking less then 1% of CPU .. then why it is showing above 50% of overall CPU. please find command output below and help me to resolve this issue.

 

 

Router#sh processes cpu sorted

CPU utilization for five seconds: 56%/53%; one minute: 59%; five minutes: 60%

PID Runtime(ms)     Invoked      uSecs   5Sec   1Min   5Min TTY Process

  41   681415332    30127352      22618  1.67%  1.63%  1.62%   0 Per-Second Jobs

163    11000012  3023208218          0  0.55%  0.57%  0.57%   0 HQF Shaper Backg

  18        3448        4509        764  0.23%  0.04%  0.12% 706 SSH Process

103   129123676   456896912        282  0.15%  0.05%  0.07%   0 IP Input

   3     4320900    60229596         71  0.07%  0.03%  0.02%   0 OSPF-100 Hello

171      155380    11105028         13  0.07%  0.00%  0.00%   0 NTP

  37    58827344    21509368       2734  0.07%  0.16%  0.17%   0 Net Background

182      183920    16724026         10  0.07%  0.00%  0.00%   0 FLEX DSPRM MAIN

206      323868   150459106          2  0.07%  0.01%  0.00%   0 Atheros LED Ctro

  48       70756     9007965          7  0.07%  0.00%  0.00%   0 HC Counter Timer

  10           0           1          0  0.00%  0.00%  0.00%   0 IPC Zone Manager

PID Runtime(ms)     Invoked      uSecs   5Sec   1Min   5Min TTY Process

   9        1388      501572          2  0.00%  0.00%  0.00%   0 IPC Dynamic Cach

  11       53996    29378126          1  0.00%  0.00%  0.00%   0 IPC Periodic Tim

   8           0           1          0  0.00%  0.00%  0.00%   0 License Client N

  15           0           1          0  0.00%  0.00%  0.00%   0 OIR Handler

   7           0           2          0  0.00%  0.00%  0.00%   0 Timers

  12       47576    29378137          1  0.00%  0.00%  0.00%   0 IPC Deferred Por

  13           0           1          0  0.00%  0.00%  0.00%   0 IPC Seat Manager

  19      139608      880261        158  0.00%  0.00%  0.00%   0 ARP Input

  14           0           1          0  0.00%  0.00%  0.00%   0 IPC BackPressure

  21           0           2          0  0.00%  0.00%  0.00%   0 ATM Idle Timer

  16           0           1          0  0.00%  0.00%  0.00%   0 Crash writer

 

 

Router#sh version
Cisco IOS Software, 3800 Software (C3845-SPSERVICESK9-M), Version 12.4(24)T, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2009 by Cisco Systems, Inc.
Compiled Wed 25-Feb-09 23:14 by prod_rel_team

ROM: System Bootstrap, Version 12.4(13r)T11, RELEASE SOFTWARE (fc1)

PUN_PG1_3845_HQ uptime is 49 weeks, 5 days, 7 hours, 34 minutes
System returned to ROM by power-on
System restarted at 07:22:25 IST Sat Sep 4 2010
System image file is "flash:c3845-spservicesk9-mz.124-24.T.bin"


This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

Cisco 3845 (revision 1.0) with 222208K/39936K bytes of memory.
Processor board ID FHK1326F1T1
8 FastEthernet interfaces
2 Gigabit Ethernet interfaces
DRAM configuration is 64 bits wide with parity enabled.
447K bytes of NVRAM.
62720K bytes of ATA System CompactFlash (Read/Write)

Configuration register is 0x2102

 

Let me know if you required any other info or output.

 

Thanks |

 

Aks

  • Parvesh Paliwal 97 posts since
    Sep 24, 2009
    Currently Being Moderated
    2. Aug 22, 2011 1:11 AM (in response to aks)
    Re: High CPU Utilization on 3845 router

    Hoping it helps you... revert back if required,

    CPU profiling is a low-overhead way of determining where the CPU spends its time. The system works by sampling the processor location every four milliseconds. The count for that location in memory is incremented. The root cause of this CPU utilization will be determined by CPU Profiling.

    Complete these steps in order to perform CPU profiling. CPU utilization has be done when you are experiencing high CPU utilization.

    Note: All these commands must be typed when in enable mode

    1. Capture the output of show region and take the starting address, the ending address and the size of main:text region
    2. Capture the output of show memory statistics and check the size of the largest block in processor memory.


    3. Do profile task interrupt to configure profiling only for interrupts.

       


    4. Compare the size of main:text region with the size of the largest block of free processor memory. Ideally the largest block should be larger than the main:text.

      If the largest block is smaller than main:text size, then adjust the granularity to make sure that the profiling will be able to get a block of processor memory.

      If the largest block is larger than main:text region, use a granularity of 4.

      If the largest block is larger than the half of the main:text region, use a granularity of 8.

      If the largest block is larger than a quarter of the main:text region, use a granularity of 10 ( 16 in hexadecimal).

      Note: Granularity must be a power of 2 and should be as small as possible (but not smaller than 4)


    5. Start profiling by doing profile

      Profile <starting address> <ending address> <granularity value>

      The starting address and ending address is determined from the Step1.


    6. Wait 5 to 10 minutes


    7. Stop profiling by doing profile stop


    8. Capture the output of show profile terse.


    9. Make sure the memory is freed by doing unprofile all


  • James 584 posts since
    Jun 29, 2008
    Currently Being Moderated
    3. Aug 22, 2011 1:26 AM (in response to aks)
    Re: High CPU Utilization on 3845 router

    sometimes they do go that high, it could be from the IOS with a bug in it, ot since it is a router, it is processing all the data it needs to route the traffic.

    You have to do a show process cpu over time to see if it comes down or not.

    Sometimes it just might be the IOS causing this problem. I have the same thing with the core i am using.

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