4.2. Analyzing the Environment

It is recommended to run the Log Collection Analysis tool and the Image Discrepancies tool prior to performing updates and for troubleshooting. These tools analyze your environment for known issues that might prevent you from performing an update, and provide recommendations to resolve them.

4.2.1. Log Collection Analysis tool

Run the Log Collection Analysis tool prior to performing updates and for troubleshooting. The tool analyzes your environment for known issues that might prevent you from performing an update, and provides recommendations to resolve them. The tool gathers detailed information about your system and presents it as an HTML file.

Prerequisites

  • Ensure the Manager has the correct repositories enabled. For the list of required repositories, see Enabling the Red Hat Virtualization Manager Repositories for Red Hat Virtualization 4.3.

    Updates to the Red Hat Virtualization Manager are released through the Content Delivery Network.

Procedure

  1. Install the Log Collection Analysis tool on the Manager machine:

    # yum install rhv-log-collector-analyzer
  2. Run the tool:

    # rhv-log-collector-analyzer --live

    A detailed report is displayed.

    By default, the report is saved to a file called analyzer_report.html.

    To save the file to a specific location, use the --html flag and specify the location:

    # rhv-log-collector-analyzer --live --html=/directory/filename.html
  3. You can use the ELinks text mode web browser to read the analyzer reports within the terminal. To install the ELinks browser:

    # yum install -y elinks
  4. Launch ELinks and open analyzer_report.html.

    # elinks /home/user1/analyzer_report.html

    To navigate the report, use the following commands in ELinks:

    • Insert to scroll up
    • Delete to scroll down
    • PageUp to page up
    • PageDown to page down
    • Left Bracket to scroll left
    • Right Bracket to scroll right

4.2.2. Image Discrepancies tool

The RHV Image Discrepancies tool analyzes image data in the Storage Domain and RHV Database. It alerts you if it finds discrepancies in volumes and volume attributes, but does not fix those discrepancies. Use this tool in a variety of scenarios, such as:

  • Before upgrading versions, to avoid carrying over broken volumes or chains to the new version.
  • Following a failed storage operation, to detect volumes or attributes in a bad state.
  • After restoring the RHV database or storage from backup.
  • Periodically, to detect potential problems before they worsen.
  • To analyze a snapshot- or live storage migration-related issues, and to verify system health after fixing these types of problems.

Prerequisites

  • Required Versions: this tool was introduced in RHV version 4.3.8 with rhv-log-collector-analyzer-0.2.15-0.el7ev.
  • Because data collection runs simultaneously at different places and is not atomic, stop all activity in the environment that can modify the storage domains. That is, do not create or remove snapshots, edit, move, create, or remove disks. Otherwise, false detection of inconsistencies may occur. Virtual Machines can remain running normally during the process.

Procedure

  1. To run the tool, enter the following command on the RHV Manager:

    # rhv-image-discrepancies
  2. If the tool finds discrepancies, rerun it to confirm the results, especially if there is a chance some operations were performed while the tool was running.
Note
This tool includes any Export and ISO storage domains and may report discrepancies for them. If so, these can be ignored, as these storage domains do not have entries for images in the {virt-product-shortname} database.

Understanding the results

The tool reports the following:

  • If there are volumes that appear on the storage but are not in the database, or appear in the database but are not on the storage.
  • If some volume attributes differ between the storage and the database.

Sample output:

 Checking storage domain c277ad93-0973-43d9-a0ca-22199bc8e801
    Looking for missing images...
    No missing images found
    Checking discrepancies between SD/DB attributes...
    image ef325650-4b39-43cf-9e00-62b9f7659020 has a different attribute capacity on storage(2696984576) and on DB(2696986624)
    image 852613ce-79ee-4adc-a56a-ea650dcb4cfa has a different attribute capacity on storage(5424252928) and on DB(5424254976)

 Checking storage domain c64637b4-f0e8-408c-b8af-6a52946113e2
    Looking for missing images...
    No missing images found
    Checking discrepancies between SD/DB attributes...
    No discrepancies found

You can now update the Manager to the latest version of 4.3.