ceph/doc/cluster-ops/pg-states.rst
John Wilkins 31b1c2f84a doc: Added PG states.
Signed-off-by: John Wilkins <john.wilkins@inktank.com>
2012-09-04 11:40:25 -07:00

64 lines
2.1 KiB
ReStructuredText

========================
Placement Group States
========================
When checking a cluster's status (e.g., running ``ceph -w`` or ``ceph -s``),
Ceph will report on the status of the placement groups. A placement group has
one or more states. The optimum state for placement groups in the placement group
map is ``active + clean``.
*Creating*
Ceph is still creating the placement group.
*Active*
Ceph will process requests to the placement group.
*Clean*
Ceph replicated all objects in the placement group the correct number of times.
*Down*
A replica with necessary data is down, so the placement group is offline.
*Replay*
The placement group is waiting for clients to replay operations after an OSD crashed.
*Splitting*
Ceph is splitting the placment group into multiple placement groups. (functional?)
*Scrubbing*
Ceph is checking the placement group for inconsistencies.
*Degraded*
Ceph has not replicated some objects in the placement group the correct number of times yet.
*Inconsistent*
Ceph detects inconsistencies in the one or more replicas of an object in the placement group
(e.g. objects are the wrong size, objects are missing from one replica *after* recovery finished, etc.).
*Peering*
The placement group is undergoing the peering process
*Repair*
Ceph is checking the placement group and repairing any inconsistencies it finds (if possible).
*Recovering*
Ceph is migrating/synchronizing objects and their replicas.
*Backfill*
Ceph is scanning and synchronizing the entire contents of a placement group
instead of inferring what contents need to be synchronized from the logs of
recent operations. *Backfill* is a special case of recovery.
*Incomplete*
Ceph detects that a placement group is missing a necessary period of history
from its log. If you see this state, report a bug, and try to start any
failed OSDs that may contain the needed information.
*Stale*
The placement group is in an unknown state - the monitors have not received
an update for it since the placement group mapping changed.
*Remapped*
The placement group is temporarily mapped to a different set of OSDs from what
CRUSH specified.