OSDs store PGs and each PG contains objects. The overall health of a cluster depends majorly on PGs. The cluster will remain in a HEALTH_OK status only if all the PGs are on the status, active+clean. If your Ceph cluster is not healthy, then there are chances that the PGs are not active+clean. Placement groups can exhibit multiple states and even combinations of states. The following are some states that a PG can be:
- Creating: The PG is being created.
- Peering: The process of bringing all of the OSDs that store PGs into agreement about the state of all objects including their metadata in that PG.
- Active: Once the peering operation is completed, Ceph lists the PG as active. Under the active state, the data in the PG data is ...