placement-group · shipping · also Ceph placement group, PG

Placement group (Ceph)

In Ceph, a placement group is a logical grouping of objects within a pool that share storage placement and are managed together for replication and recovery.

Related Observatory article: Placement group (Ceph) on hesela.com

Ceph maps objects to placement groups and maps those groups to Object Storage Daemons (OSDs). [2] One OSD can hold data from many placement groups, so a placement group is not a dedicated physical disk or a failure domain. More placement groups can improve distribution but consume CPU, memory and network resources. [1]

Relations

related

failure-domain, crush-placement, ceph-up-set, ceph-acting-set, ceph-peering

Citations

1. Ceph Squid documentation: Placement Groups, use and resource costs (accessed 2026-10-13)
2. Ceph Squid glossary: Ceph OSD means Object Storage Daemon (accessed 2026-10-13)
3. Storage availability and correlated failures: placement boundaries (accessed 2026-10-13)

JSON: /data/terms/placement-group.json