Glossary #

General

Admin node #

The host from which you run the Ceph-related commands to administer cluster hosts.

Alertmanager #

A single binary which handles alerts sent by the Prometheus server and notifies the end user.

archive sync module #

Module that enables creating an Object Gateway zone for keeping the history of S3 object versions.

Bucket #

A point that aggregates other nodes into a hierarchy of physical locations.

Ceph Client #

The collection of Ceph components which can access a Ceph Storage Cluster. These include the Object Gateway, the Ceph Block Device, the CephFS, and their corresponding libraries, kernel modules, and FUSE clients.

Ceph Dashboard #

A built-in Web-based Ceph management and monitoring application to administer various aspects and objects of the cluster. The dashboard is implemented as a Ceph Manager module.

Ceph Manager #

Ceph Manager or MGR is the Ceph manager software, which collects all the state from the whole cluster in one place.

Ceph Monitor #

Ceph Monitor or MON is the Ceph monitor software.

Ceph Object Storage #

The object storage "product", service or capabilities, which consists of a Ceph Storage Cluster and a Ceph Object Gateway.

Ceph OSD Daemon #

The ceph-osd daemon is the component of Ceph that is responsible for storing objects on a local file system and providing access to them over the network.

Ceph Storage Cluster #

The core set of storage software which stores the user's data. Such a set consists of Ceph monitors and OSDs.

ceph-salt #

Provides tooling for deploying Ceph clusters managed by cephadm using Salt.

cephadm #

cephadm deploys and manages a Ceph cluster by connecting to hosts from the manager daemon via SSH to add, remove, or update Ceph daemon containers.

CephFS #

The Ceph file system.

CephX #

The Ceph authentication protocol. Cephx operates like Kerberos, but it has no single point of failure.

CRUSH rule #

The CRUSH data placement rule that applies to a particular pool or pools.

CRUSH, CRUSH Map #

Controlled Replication Under Scalable Hashing: An algorithm that determines how to store and retrieve data by computing data storage locations. CRUSH requires a map of the cluster to pseudo-randomly store and retrieve data in OSDs with a uniform distribution of data across the cluster.

DriveGroups #

DriveGroups are a declaration of one or more OSD layouts that can be mapped to physical drives. An OSD layout defines how Ceph physically allocates OSD storage on the media matching the specified criteria.

Grafana #

Database analytics and monitoring solution.

Metadata Server #

Metadata Server or MDS is the Ceph metadata software.

Multi-zone #

Node #

Any single machine or server in a Ceph cluster.

Object Gateway #

The S3/Swift gateway component for Ceph Object Store. Also known as the RADOS Gateway (RGW).

OSD #

Object Storage Device: A physical or logical storage unit.

OSD node #

A cluster node that stores data, handles data replication, recovery, backfilling, rebalancing, and provides some monitoring information to Ceph monitors by checking other Ceph OSD daemons.

PG #

Placement Group: a sub-division of a pool, used for performance tuning.

Point Release #

Any ad-hoc release that includes only bug or security fixes.

Pool #

Logical partitions for storing objects such as disk images.

Prometheus #

Systems monitoring and alerting toolkit.

RADOS Block Device (RBD) #

The block storage component of Ceph. Also known as the Ceph block device.

Reliable Autonomic Distributed Object Store (RADOS) #

The core set of storage software which stores the user's data (MON+OSD).

Routing tree #

A term given to any diagram that shows the various routes a receiver can run.

Rule Set #

Rules to determine data placement for a pool.

Samba #

Windows integration software.

Samba Gateway #

The Samba Gateway joins the Active Directory in the Windows domain to authenticate and authorize users.

zonegroup #