Troubleshooting checklist

Edit online
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:

  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 an operating system patch applied?
    • Did the network environment change? For example, was a server moved or a domain migrated?
    • Did the system recently fail or abnormally terminate?
  4. If you know (for example, based on message prefixes or error codes), where does the problem occur? On one or more systems, production or 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 z16 or IBM z14 ZR1.
  • Which driver and bundle is installed.
  • Storage server, for example, DS8000®.
  • Storage attachment, for example FICON®, or FCP.
  • Disk configuration.
  • Network, for example OSA (type, mode), HiperSockets.
  • Network topologies.
  • Middleware setup (databases, web servers, SAP, or Tivoli Storage Manager. 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.