Ceph/Object Store Device

The Ceph object store device represents a storage area for Ceph in which objects can be placed. When a user or application places objects inside a Ceph cluster, a pool is passed. Based on the pool and the object name, the correct placement group is deduced.

Each placement group has a distribution map (which Ceph calls the CRUSH map) that informs Ceph how the object should be stored (which OSDs take part) whereas the pool itself contains information on how many replicas of the object should be made.

Mounting
The default location where an OSD daemon stores its objects is at. For instance, the OSD daemon with id 0 in a Ceph cluster called ceph will have its location at.

This is of course configurable through the configuration file.