Managing the operational state of your Ceph cluster services is fundamental for maintaining system health and availability. Effectively controlling the service lifecycle involves understanding how to start, stop, and restart individual components or entire service types across the cluster.
The modern approach leverages the Ceph orchestrator, typically cephadm, to manage services at a higher level. This allows you to issue commands that the orchestrator executes across the relevant nodes. For instance, you can stop all Object Storage Daemons (OSDs) or start all Monitor services with simple, declarative commands. The orchestrator handles the complexities of coordinating these actions. You can also enable or disable services to control whether they automatically start on boot or are prevented from starting.
Alternatively, for managing specific instances of a daemon on a particular host, traditional system service managers like systemctl can be used. This provides granular control over a single daemon process, allowing you to restart a problematic OSD or stop a specific monitor. However, using the orchestrator for cluster-wide actions is generally recommended as it maintains the desired state defined for the Ceph cluster.
Understanding both methods ensures you have the flexibility to manage your Ceph services efficiently, whether dealing with a single daemon issue or performing planned maintenance across your entire storage system. Proper service management is key to a robust and reliable Ceph environment.
Source: https://kifarunix.com/how-to-start-stop-or-restart-ceph-services/
