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Troubleshoot service errors on start

Hands-On Lab

 

Photo of Michael Christian

Michael Christian

Course Development Director in Content

Length

01:30:00

Difficulty

Advanced

In this exercise, you will troubleshoot and resolve service errors upon start of the pmcd service.

What are Hands-On Labs?

Hands-On Labs are scenario-based learning environments where learners can practice without consequences. Don't compromise a system or waste money on expensive downloads. Practice real-world skills without the real-world risk, no assembly required.

Troubleshoot service errors on start

Introduction

In this exercise, you will troubleshoot and resolve service errors upon start of the pmcd service.

Another administrator has escalated an issue regarding startup of the pmcd service. They are unable to successfully start the service.

Solution

Start by logging in to the lab servers using the credentials provided on the hands-on lab page:

ssh cloud_user@PUBLIC_IP_ADDRESS

Become the root user:

sudo su -

Resolve the startup issue with pmcd

  1. Attempt to start the pmcd service:

    systemctl start pmcd
  2. If the service fails to start, take a look at the details:

    systemctl status -l pmcd

    Note the "Drop-In" file /etc/systemd/system/pmcd.service.d/dependency.conf.

  3. View the contents of this file and note any directives referencing other services:

    cat /etc/systemd/system/pmcd.service.d/dependency.conf
  4. Attempt to start the pmlogger service:

    systemctl start pmlogger

    If the service won't start, perform the same exercise as above with pmcd.

  5. Resolve the cyclical dependency by modifying the pmcd drop-in file from After=pmlogger.service to Before=pmlogger.service.

    vim /etc/systemd/system/pmcd.service.d/dependency.conf
  6. Start the pmcd service:

    systemctl start pmcd
  7. Verify pmlogger is running:

    systemctl status pmlogger

Configure pmcd to start by default

  1. Enable pmcd to startup upon reboot:

    systemctl enable pmcd

Conclusion

Congratulations, you've completed this hands-on lab!