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Dick_Dastardly's avatar
Dick_Dastardly
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Oct 10, 2023
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"Core the device" - what actually happens

I have read comments that certain bad settings, or irules, can cause the device to "core".

Whilst I understand that this is a bad thing to be avoided at all costs what actually happens when the device cores?

And what would the recovery steps look like?

  • Hi Dick_Dastardly , 
    Core files are created for multiple reasons and finding them in your Bigip indicate that something abnormal happened , for instance : 
    >> CPU may reach 100 % , so bigip will create core file contains the reasons that made CPU to reach 100 %. 
    >> Restarting Bigip services such as ( pccd , mcpd , or bd crashing ..... ) , bigip will create core dump for this.
    >> Something caused your bigip to reboot , after opening you will find core dump file. 
    >> and other abnormal behaviors can make bigip ip to core. 

    So in my opinion , if you troubleshoot during a critical issue related to bigip, you should check first if there are core dump files were created or not. 
    >> if you find core file , you must raise a case with F5 support immediately , as Support team is the only direction to help you in reading core files and extract the Root cause for your issue , they equiped sufficiently  to support in this matter. 

    >> if you didn't find any core files created , you should proceed in your troubleshooting and see other possibilities that may casued this issue. 

    Core files are located in this direction , you can navigate it using CLI " Command line interface " : 

     

     

     

    ls -latr /var/core/

     

     

     


    Also Take a quick look on this article to know how to manage core files : 
    https://my.f5.com/manage/s/article/K10062

    I hope my comment helps you 🙂 

3 Replies

  • Hi Dick_Dastardly , 
    Core files are created for multiple reasons and finding them in your Bigip indicate that something abnormal happened , for instance : 
    >> CPU may reach 100 % , so bigip will create core file contains the reasons that made CPU to reach 100 %. 
    >> Restarting Bigip services such as ( pccd , mcpd , or bd crashing ..... ) , bigip will create core dump for this.
    >> Something caused your bigip to reboot , after opening you will find core dump file. 
    >> and other abnormal behaviors can make bigip ip to core. 

    So in my opinion , if you troubleshoot during a critical issue related to bigip, you should check first if there are core dump files were created or not. 
    >> if you find core file , you must raise a case with F5 support immediately , as Support team is the only direction to help you in reading core files and extract the Root cause for your issue , they equiped sufficiently  to support in this matter. 

    >> if you didn't find any core files created , you should proceed in your troubleshooting and see other possibilities that may casued this issue. 

    Core files are located in this direction , you can navigate it using CLI " Command line interface " : 

     

     

     

    ls -latr /var/core/

     

     

     


    Also Take a quick look on this article to know how to manage core files : 
    https://my.f5.com/manage/s/article/K10062

    I hope my comment helps you 🙂