### Understand the alert

This alert is triggered when a `systemd slice unit` enters a `failed state`. Systemd slice units are a way to organize and manage system processes in a hierarchical manner. If you receive this alert, it means that there is an issue with a specific slice unit, which can be crucial for system stability and performance.

### What does the failed state mean?

A `failed state` in the context of systemd units means that the unit has encountered a problem and is not functioning properly. This could be caused by a variety of reasons, such as misconfiguration, dependency issues, or unhandled errors in the underlying service.

### Troubleshoot the alert

- Identify the problematic systemd slice unit.

  Run the following command to list all systemd units and their states:

  ```bash
  systemctl --all
  ```

  Look for the units with the `failed` state in the output, and take note of the affected unit(s).

- Investigate the specific issue with the failed unit.

  Use the `systemctl status` command followed by the unit name to get more information about the problem:

  ```bash
  systemctl status <unit-name>
  ```

  The output will provide more details on the issue and may include error messages or log entries that can help identify the root cause.

- Check the unit logs for additional clues.

  The `journalctl` command can be used to view the logs related to a specific unit by specifying the `-u` flag followed by the unit name:

  ```bash
  journalctl -u <unit-name>
  ```

  Analyze the log entries for any reported errors or warnings that could be related to the failure.

- Address the root cause of the issue.

  Based on the information gathered, take the necessary steps to resolve the issue with the failed unit. This may involve reconfiguring the unit, adjusting dependencies, or fixing the underlying service.

- Restart the unit and verify its status.

  Once the issue has been resolved, restart the systemd unit using the `systemctl restart` command:

  ```bash
  systemctl restart <unit-name>
  ```

  Afterwards, check the unit's status to confirm that it is no longer in a failed state and is functioning properly:

  ```bash
  systemctl status <unit-name>
  ```

