As a storage administrator, you would need to keep an eye on your Ceph storage cluster and find out what's going on at a given time. Regular and disciplined monitoring keeps you updated with your cluster health. Based on monitoring notifications, you would get a bit more time to take necessary action before service outages.

Monitoring a Ceph cluster is an everyday task that includes the monitoring of MON, OSD, MDS, PG, as well as storage provisioning services such as RBD, Radosgw, CephFS, and Ceph clients. Ceph, by default, comes with a rich set of native command line tools and API to perform monitoring on these components. In addition to this, there are also open source projects that are intentionally developed for monitoring Ceph clusters on a GUI one-view dashboard. In the following recipes, we will focus on Ceph CLI tools for cluster monitoring.