Book Image

Mastering Ceph

By : Nick Fisk
Book Image

Mastering Ceph

By: Nick Fisk

Overview of this book

Mastering Ceph covers all that you need to know to use Ceph effectively. Starting with design goals and planning steps that should be undertaken to ensure successful deployments, you will be guided through to setting up and deploying the Ceph cluster, with the help of orchestration tools. Key areas of Ceph including Bluestore, Erasure coding and cache tiering will be covered with help of examples. Development of applications which use Librados and Distributed computations with shared object classes are also covered. A section on tuning will take you through the process of optimisizing both Ceph and its supporting infrastructure. Finally, you will learn to troubleshoot issues and handle various scenarios where Ceph is likely not to recover on its own. By the end of the book, you will be able to successfully deploy and operate a resilient high performance Ceph cluster.
Table of Contents (12 chapters)

Ceph logging

When investigating errors, it is very handy to be able to look through the Ceph log files to get a better idea of what is going on. By default, the logging levels are set so that only the important events are logged. During troubleshooting the logging levels may need to be increased in order to reveal the cause of the error. To increase the logging level, you can either edit ceph.conf , add the new logging level, and then restart the component, or, if you don’t wish to restart the Ceph daemons, you can inject the new configuration parameter into the live running daemon. To inject parameters, use the ceph tell command:

ceph tell osd.0 injectargs --debug-osd 0/5

Then, set the logging level for the OSD log on osd.0 to 0/5. The number 0 is the disk logging level, and the number 5 is the in memory logging level.

At a logging level of 20, the logs are extremely verbose and will grow quickly. Do not...