mirror of https://github.com/ceph/ceph
188 lines
5.3 KiB
ReStructuredText
188 lines
5.3 KiB
ReStructuredText
===============
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Ceph Glossary
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===============
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Ceph is growing rapidly. As firms deploy Ceph, the technical terms such as
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"RADOS", "RBD," "RGW" and so forth require corresponding marketing terms
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that explain what each component does. The terms in this glossary are
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intended to complement the existing technical terminology.
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Sometimes more than one term applies to a definition. Generally, the first
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term reflects a term consistent with Ceph's marketing, and secondary terms
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reflect either technical terms or legacy ways of referring to Ceph systems.
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.. glossary::
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Ceph Project
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The aggregate term for the people, software, mission and infrastructure
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of Ceph.
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cephx
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The Ceph authentication protocol. Cephx operates like Kerberos, but it
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has no single point of failure.
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Ceph
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Ceph Platform
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All Ceph software, which includes any piece of code hosted at
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`https://github.com/ceph`_.
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Ceph System
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Ceph Stack
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A collection of two or more components of Ceph.
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Ceph Node
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Node
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Host
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Any single machine or server in a Ceph System.
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Ceph Storage Cluster
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Ceph Object Store
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RADOS
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RADOS Cluster
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Reliable Autonomic Distributed Object Store
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The core set of storage software which stores the user's data (MON+OSD).
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Ceph Cluster Map
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cluster map
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The set of maps comprising the monitor map, OSD map, PG map, MDS map and
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CRUSH map. See `Cluster Map`_ for details.
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Ceph Object Storage
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The object storage "product", service or capabilities, which consists
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essentially of a Ceph Storage Cluster and a Ceph Object Gateway.
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Ceph Object Gateway
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RADOS Gateway
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RGW
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The S3/Swift gateway component of Ceph.
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Ceph Block Device
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RBD
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The block storage component of Ceph.
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Ceph Block Storage
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The block storage "product," service or capabilities when used in
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conjunction with ``librbd``, a hypervisor such as QEMU or Xen, and a
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hypervisor abstraction layer such as ``libvirt``.
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Ceph Filesystem
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CephFS
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Ceph FS
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The POSIX filesystem components of Ceph.
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Cloud Platforms
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Cloud Stacks
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Third party cloud provisioning platforms such as OpenStack, CloudStack,
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OpenNebula, ProxMox, etc.
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Object Storage Device
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OSD
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A physical or logical storage unit (*e.g.*, LUN).
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Sometimes, Ceph users use the
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term "OSD" to refer to :term:`Ceph OSD Daemon`, though the
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proper term is "Ceph OSD".
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Ceph OSD Daemon
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Ceph OSD Daemons
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Ceph OSD
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The Ceph OSD software, which interacts with a logical
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disk (:term:`OSD`). Sometimes, Ceph users use the
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term "OSD" to refer to "Ceph OSD Daemon", though the
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proper term is "Ceph OSD".
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OSD id
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The integer that defines an OSD. It is generated by the monitors as part
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of the creation of a new OSD.
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OSD fsid
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This is a unique identifier used to further improve the uniqueness of an
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OSD and it is found in the OSD path in a file called ``osd_fsid``. This
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``fsid`` term is used interchangeably with ``uuid``
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OSD uuid
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Just like the OSD fsid, this is the OSD unique identifer and is used
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interchangeably with ``fsid``
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bluestore
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OSD BlueStore is a new back end for OSD daemons (kraken and newer
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versions). Unlike :term:`filestore` it stores objects directly on the
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Ceph block devices without any file system interface.
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filestore
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A back end for OSD daemons, where a Journal is needed and files are
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written to the filesystem.
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Ceph Monitor
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MON
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The Ceph monitor software.
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Ceph Manager
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MGR
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The Ceph manager software, which collects all the state from the whole
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cluster in one place.
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Ceph Metadata Server
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MDS
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The Ceph metadata software.
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Ceph Clients
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Ceph Client
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The collection of Ceph components which can access a Ceph Storage
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Cluster. These include the Ceph Object Gateway, the Ceph Block Device,
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the Ceph Filesystem, and their corresponding libraries, kernel modules,
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and FUSEs.
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Ceph Kernel Modules
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The collection of kernel modules which can be used to interact with the
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Ceph System (e.g., ``ceph.ko``, ``rbd.ko``).
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Ceph Client Libraries
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The collection of libraries that can be used to interact with components
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of the Ceph System.
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Ceph Release
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Any distinct numbered version of Ceph.
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Ceph Point Release
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Any ad-hoc release that includes only bug or security fixes.
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Ceph Interim Release
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Versions of Ceph that have not yet been put through quality assurance
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testing, but may contain new features.
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Ceph Release Candidate
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A major version of Ceph that has undergone initial quality assurance
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testing and is ready for beta testers.
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Ceph Stable Release
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A major version of Ceph where all features from the preceding interim
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releases have been put through quality assurance testing successfully.
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Ceph Test Framework
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Teuthology
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The collection of software that performs scripted tests on Ceph.
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CRUSH
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Controlled Replication Under Scalable Hashing. It is the algorithm
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Ceph uses to compute object storage locations.
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CRUSH rule
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The CRUSH data placement rule that applies to a particular pool(s).
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Pool
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Pools
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Pools are logical partitions for storing objects.
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systemd oneshot
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A systemd ``type`` where a command is defined in ``ExecStart`` which will
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exit upon completion (it is not intended to daemonize)
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LVM tags
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Extensible metadata for LVM volumes and groups. It is used to store
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Ceph-specific information about devices and its relationship with
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OSDs.
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.. _https://github.com/ceph: https://github.com/ceph
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.. _Cluster Map: ../architecture#cluster-map
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