Placement group states

When you check the storage cluster’s status with the ceph -s or ceph -w commands, Ceph reports on the status of the placement groups (PGs). A PG has one or more states. The optimum state for PGs in the PG map is an active + clean state. Use this information to get to know the different placement group states.

activating
The PG is peered, but not yet active.
active
Ceph processes requests to the PG.
backfill_toofull
A backfill operation is waiting because the destination OSD is over the backfillfull ratio.
backfill_unfound
Backfill stopped due to unfound objects.
backfill_wait
The PG is waiting in line to start backfill.
backfilling
Ceph is scanning and synchronizing the entire contents of a PG instead of inferring what contents need to be synchronized from the logs of recent operations. Backfill is a special case of recovery.
clean
Ceph replicated all objects in the PG accurately.
creating
Ceph is still creating the PG.
deep
Ceph is checking the PG data against stored checksums.
degraded
Ceph has not replicated some objects in the PG accurately yet.
down
A replica with necessary data is down, so the PG is offline. A PG with less than min_size replicas is marked as down. Use ceph health detail to understand the backing OSD state.
forced_backfill
High backfill priority of that PG is enforced by user.
forced_recovery
High recovery priority of that PG is enforced by user.
incomplete
Ceph detects that a PG is missing information about writes that might have occurred, or does not have any healthy copies. If you see this state, try to start any failed OSDs that might contain the needed information. In the case of an erasure coded pool, temporarily reducing min_size might allow recovery.
inconsistent
Ceph detects inconsistencies in one or more replicas of an object in the PG, such as objects are the wrong size, objects are missing from one replica after recovery finished.
peering
The PG is undergoing the peering process. A peering process should clear off without much delay, but if it stays and the number of PGs in a peering state does not reduce in number, the peering might be stuck.
peered
The PG has peered, but cannot serve client IO due to not having enough copies to reach the pool’s configured min_size parameter. Recovery might occur in this state, so the PG might heal up to min_size eventually.
recovering
Ceph is migrating or synchronizing objects and their replicas.
recovery_toofull
A recovery operation is waiting because the destination OSD is over its full ratio.
recovery_unfound
Recovery stopped due to unfound objects.
recovery_wait
The PG is waiting in line to start recovery.
remapped
The PG is temporarily mapped to a different set of OSDs from what CRUSH specified.
repair
Ceph is checking the PG and repairing any inconsistencies it finds, if possible.
replay
The PG is waiting for clients to replay operations after an OSD crashed.
snaptrim
Trimming snaps.
snaptrim_error
Error stopped trimming snaps.
snaptrim_wait
Queued to trim snaps.
scrubbing
Ceph is checking the PG metadata for inconsistencies.
splitting
Ceph is splitting the PG into multiple PGs.
stale
The PG is in an unknown state; the monitors have not received an update for it since the PG mapping changed.
undersized
The PG has fewer copies than the configured pool replication level.
unknown
The ceph-mgr has not yet received any information about the PG’s state from an OSD since Ceph Manager started up.