Troubleshooting checklist

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When you report a problem, provide as much information as possible about the circumstances.

Answering the following questions can help you or IBM® support to determine the cause for problems that occur with Linux® on IBM Z and IBM LinuxONE:

  1. How does the problem manifest itself? What are the symptoms?
    • When this problem occurs, is a specific error message or error code issued?
    • Is trace output of the operation available?
  2. How long has the problem been occurring?
    • Is it a first time occurrence? When did it happen? (Date and time help to analyze the logs.)
    • How frequently does it occur?
    • Is there any pattern?
  3. If the problem occurred subsequent to some period of normal operation, did anything change in the environment?
    • Was a maintenance code or microcode applied to the hardware components?
    • Did the network environment change? For example, was a server moved or a domain migrated?
    • Did the system recently fail or abnormally terminate?
  4. Are you able to identify involved components and systems where the problem occur?
    • Do message prefixes or error codes allow an identification?
    • Are one or more systems showing the same issue or symptoms?
    • Is the issue encountered in a production or a test environment?
  5. Can you reproduce the problem on a test system (so that you do not negatively affect the production environment)? What steps are required to reproduce the problem?
  6. How many users are impacted?
    • Does this problem affect one, some, or all users?
    • Does the problem occur only for a user who was recently added to the environment, such as a new employee?
    • Do differences exist between the users who are affected and the users who are not affected?
  7. How many applications or business processes are impacted?
    • Does this problem affect one, some, or all applications or business processes?
    • Does the problem occur only for a new application or business process?
    • Do differences exist between the applications or business processes that are affected and the applications or business processes that are not affected by the problem?
In your report, describe the server and storage infrastructure in as much detail as possible:
  • Machine setup, for example, IBM z17 ™ or IBM LinuxONE 4 Rockhopper.
  • Which driver and bundle is installed.
  • Storage server, for example, DS8000®.
  • Storage attachment, for example FICON®, FCP or NVME.
  • Disk configuration.
  • Network, type and model, for example OSA, HiperSockets™ or PCI cards.
  • Network topologies including switch types.
  • Virtualization environment, for example z/VM guest, KVM host, KVM guest or LPAR environment.
  • Middleware setup (databases or web servers. Include version information, if relevant).

You can now collect additional diagnostic data that is required for an IBM technical-support representative to effectively troubleshoot the problem.