==================
When you start the Ceph service, the initialization process activates a series
-of daemons that run in the background. All Ceph clusters run two types of
-daemons:
+of daemons that run in the background. A :term:`Ceph Storage Cluster` runs
+two types of daemons:
-- Monitor (``ceph-mon``)
-- Object Storage Device (``ceph-osd``)
+- :term:`Ceph Monitor` (``ceph-mon``)
+- :term:`Ceph OSD Daemon` (``ceph-osd``)
-Clusters that support CephFS run Metadata Servers (``ceph-mds``). Clusters that
-support a RESTful object store run Ceph Gateways (``radosgw``). For your
-convenience, each daemon has a series of default values (*i.e.*, many are set by
+Ceph Storage Clusters that support the :term:`Ceph Filesystem` run at least one
+:term:`Ceph Metadata Server` (``ceph-mds``). Clusters that support :term:`Ceph
+Object Storage` run Ceph Gateway daemons (``radosgw``). For your convenience,
+each daemon has a series of default values (*i.e.*, many are set by
``ceph/src/common/config_opts.h``). You may override these settings with a Ceph
configuration file.
The Configuration File
======================
-When you start a Ceph cluster, each daemon looks for a Ceph configuration file
-(i.e., ``ceph.conf`` by default) that provides the cluster's configuration
-settings. For manual deployments, you need to create a Ceph configuration file.
-For tools that create configuration files for you (*e.g.*, ``ceph-deploy``,
-Chef, etc.), you may use the information contained herein as a reference. The
-Ceph Configuration file defines:
+When you start a Ceph Storage Cluster, each daemon looks for a Ceph
+configuration file (i.e., ``ceph.conf`` by default) that provides the cluster's
+configuration settings. For manual deployments, you need to create a Ceph
+configuration file. For tools that create configuration files for you (*e.g.*,
+``ceph-deploy``, Chef, etc.), you may use the information contained herein as a
+reference. The Ceph configuration file defines:
- Cluster Identity
- Authentication settings
- Paths to data
- Other runtime options
-The default ``ceph.conf`` locations in sequential order include:
+The default Ceph configuration file locations in sequential order include:
#. ``$CEPH_CONF`` (*i.e.,* the path following the ``$CEPH_CONF``
environment variable)
Config Sections
===============
-The configuration file can configure all daemons in a cluster, or all daemons of
-a particular type. To configure a series of daemons, the settings must be
-included under the processes that will receive the configuration as follows:
+The configuration file can configure all Ceph daemons in a Ceph Storage Cluster,
+or all Ceph daemons of a particular type. To configure a series of daemons, the
+settings must be included under the processes that will receive the
+configuration as follows:
``[global]``
-:Description: Settings under ``[global]`` affect all daemons in a Ceph cluster.
+:Description: Settings under ``[global]`` affect all daemons in a Ceph Storage
+ Cluster.
+
:Example: ``auth supported = cephx``
``[osd]``
:Description: Settings under ``[osd]`` affect all ``ceph-osd`` daemons in
- the cluster, and override the same setting in ``[global]``.
+ the Ceph Storage Cluster, and override the same setting in
+ ``[global]``.
:Example: ``osd journal size = 1000``
``[mon]``
:Description: Settings under ``[mon]`` affect all ``ceph-mon`` daemons in
- the cluster, and override the same setting in ``[global]``.
+ the Ceph Storage Cluster, and override the same setting in
+ ``[global]``.
:Example: ``mon addr = 10.0.0.101:6789``
``[mds]``
:Description: Settings under ``[mds]`` affect all ``ceph-mds`` daemons in
- the cluster, and override the same setting in ``[global]``.
+ the Ceph Storage Cluster, and override the same setting in
+ ``[global]``.
:Example: ``host = myserver01``
``[client]``
-:Description: Settings under ``[client]`` affect all clients (e.g., mounted
- CephFS filesystems, mounted block devices, etc.).
+:Description: Settings under ``[client]`` affect all Ceph Clients
+ (e.g., mounted Ceph Filesystems, mounted Ceph Block Devices,
+ etc.).
:Example: ``log file = /var/log/ceph/radosgw.log``
-Global settings affect all instances of all daemon in the cluster. Use the
-``[global]`` setting for values that are common for all daemons in the cluster.
-You can override each ``[global]`` setting by:
+Global settings affect all instances of all daemon in the Ceph Storage Cluster.
+Use the ``[global]`` setting for values that are common for all daemons in the
+Ceph Storage Cluster. You can override each ``[global]`` setting by:
#. Changing the setting in a particular process type
(*e.g.,* ``[osd]``, ``[mon]``, ``[mds]`` ).
You may specify settings for particular instances of a daemon. You may specify
-an instance by entering its type, delimited by a period (.) and by the
-instance ID. The instance ID for an OSD is always numeric, but it may be
-alphanumeric for monitors and metadata servers.
+an instance by entering its type, delimited by a period (.) and by the instance
+ID. The instance ID for a Ceph OSD Daemon is always numeric, but it may be
+alphanumeric for Ceph Monitors and Ceph Metadata Servers.
.. code-block:: ini
Metavariables
=============
-Metavariables simplify cluster configuration dramatically. When a metavariable
-is set in a configuration value, Ceph expands the metavariable into a concrete
-value. Metavariables are very powerful when used within the ``[global]``,
-``[osd]``, ``[mon]`` or ``[mds]`` sections of your configuration file. Ceph
-metavariables are similar to Bash shell expansion.
+Metavariables simplify Ceph Storage Cluster configuration dramatically. When a
+metavariable is set in a configuration value, Ceph expands the metavariable into
+a concrete value. Metavariables are very powerful when used within the
+``[global]``, ``[osd]``, ``[mon]`` or ``[mds]`` sections of your configuration
+file. Ceph metavariables are similar to Bash shell expansion.
Ceph supports the following metavariables:
``$cluster``
-:Description: Expands to the cluster name. Useful when running multiple
- clusters on the same hardware.
+:Description: Expands to the Ceph Storage Cluster name. Useful when running
+ multiple Ceph Storage Clusters on the same hardware.
:Example: ``/etc/ceph/$cluster.keyring``
:Default: ``ceph``
``$type``
:Description: Expands to one of ``mds``, ``osd``, or ``mon``, depending on the
- type of the current daemon.
+ type of the instant daemon.
:Example: ``/var/lib/ceph/$type``
``$host``
-:Description: Expands to the host name of the current daemon.
+:Description: Expands to the host name of the instant daemon.
``$name``
===============
The `Hardware Recommendations`_ section provides some hardware guidelines for
-configuring the cluster. It is possible for a single host to run multiple
-daemons. For example, a single host with multiple disks or RAIDs may run one
-``ceph-osd`` for each disk or RAID. Ideally, you will have a host for a
-particular type of process. For example, one host may run ``ceph-osd`` daemons,
-another host may run a ``ceph-mds`` daemon, and other hosts may run ``ceph-mon``
-daemons.
-
-Each host has a name identified by the ``host`` setting. Monitors also specify
+configuring a Ceph Storage Cluster. It is possible for a single :term:`Ceph
+Node` to run multiple daemons. For example, a single node with multiple drives
+or RAIDs may run one ``ceph-osd`` for each drive or RAID. Ideally, you will
+have a node for a particular type of process. For example, some nodes may run
+``ceph-osd`` daemons, other nodes may run ``ceph-mds`` daemons, and still
+other nodes may run ``ceph-mon`` daemons.
+
+Each node has a name identified by the ``host`` setting. Monitors also specify
a network address and port (i.e., domain name or IP address) identified by the
``addr`` setting. A basic configuration file will typically specify only
-minimal settings for each instance of a daemon. For example:
+minimal settings for each instance of a daemon. For example:
.. code-block:: ini
[osd.0]
host = hostName
-.. important:: The ``host`` setting is the short name of the host (i.e., not
+.. important:: The ``host`` setting is the short name of the node (i.e., not
an fqdn). It is **NOT** an IP address either. Enter ``hostname -s`` on
- the command line to retrieve the name of the host. Also, this setting is
+ the command line to retrieve the name of the node. Also, this setting is
**ONLY** for ``mkcephfs`` and manual deployment. It **MUST NOT**
be used with ``chef`` or ``ceph-deploy``, as those tools will enter the
appropriate values for you.
Monitors
========
-Ceph production clusters typically deploy with a minimum 3 monitors to ensure
-high availability should a monitor instance crash. An odd number of monitors (3)
-ensures that the Paxos algorithm can determine which version of the cluster map
-is the most recent from a quorum of monitors.
+Ceph production clusters typically deploy with a minimum 3 :term:`Ceph Monitor`
+daemons to ensure high availability should a monitor instance crash. At least
+three (3) monitors ensures that the Paxos algorithm can determine which version
+of the :term:`Ceph Cluster Map` is the most recent from a majority of Ceph
+Monitors in the quorum.
.. note:: You may deploy Ceph with a single monitor, but if the instance fails,
- the lack of a monitor may interrupt data service availability.
+ the lack of other monitors may interrupt data service availability.
-Ceph monitors typically listen on port ``6789``. For example:
+Ceph Monitors typically listen on port ``6789``. For example:
.. code-block:: ini
host = hostName
mon addr = 150.140.130.120:6789
-By default, Ceph expects that you will store a monitor's data under the following path::
+By default, Ceph expects that you will store a monitor's data under the
+following path::
/var/lib/ceph/mon/$cluster-$id
.. versionadded:: Bobtail 0.56
-For Bobtail (v 0.56) and beyond, you should expressly enable or disable authentication
-in the ``[global]`` section of your Ceph configuration file. ::
+For Bobtail (v 0.56) and beyond, you should expressly enable or disable
+authentication in the ``[global]`` section of your Ceph configuration file. ::
auth cluster required = cephx
auth service required = cephx
Additionally, you should enable message signing. See `Cephx Config Reference`_
and `Cephx Authentication`_ for details.
-.. important:: When upgrading, we recommend expressly disabling authentication first,
- then perform the upgrade. Once the upgrade is complete, re-enable authentication.
+.. important:: When upgrading, we recommend expressly disabling authentication
+ first, then perform the upgrade. Once the upgrade is complete, re-enable
+ authentication.
.. _Cephx Authentication: ../../operations/authentication
.. _Cephx Config Reference: ../auth-config-ref
OSDs
====
-Ceph production clusters typically deploy OSDs where one host has one OSD daemon
-running a filestore on one data disk. A typical deployment specifies a journal
-size and whether the file store's extended attributes (XATTRs) use an
-object map (i.e., when running on the ``ext4`` filesystem). For example:
+Ceph production clusters typically deploy :term:Ceph OSD Daemons` where one node
+has one OSD daemon running a filestore on one storage drive. A typical
+deployment specifies a journal size and whether the file store's extended
+attributes (XATTRs) use an object map (i.e., when running on the ``ext4``
+filesystem). For example:
.. code-block:: ini
host = {hostname}
-By default, Ceph expects that you will store an OSD's data with the following path::
+By default, Ceph expects that you will store a Ceph OSD Daemon's data with the
+following path::
/var/lib/ceph/osd/$cluster-$id
/var/lib/ceph/osd/ceph-0
You may override this path using the ``osd data`` setting. We don't recommend
-changing the default location. Create the default directory on your OSD host. ::
+changing the default location. Create the default directory on your OSD host.
+
+::
ssh {osd-host}
sudo mkdir /var/lib/ceph/osd/ceph-{osd-number}
Heartbeats
==========
-During runtime operations, OSDs check up on other OSDs and report their
-findings to the monitor. You do not have to provide any settings. However,
-if you have network latency issues, you may wish to modify the settings.
+During runtime operations, Ceph OSD Daemons check up on other Ceph OSD Daemons
+and report their findings to the Ceph Monitor. You do not have to provide any
+settings. However, if you have network latency issues, you may wish to modify
+the settings.
See `Configuring Monitor/OSD Interaction`_ for additional details.
Runtime Changes
===============
-Ceph allows you to make changes to the configuration of an ``ceph-osd``,
+Ceph allows you to make changes to the configuration of a ``ceph-osd``,
``ceph-mon``, or ``ceph-mds`` daemon at runtime. This capability is quite
useful for increasing/decreasing logging output, enabling/disabling debug
settings, and even for runtime optimization. The following reflects runtime
Replace ``{daemon-type}`` with one of ``osd``, ``mon`` or ``mds``. You may apply
the runtime setting to all daemons of a particular type with ``*``, or specify
a specific daemon's ID (i.e., its number or letter). For example, to increase
-debug logging for a ``ceph-osd`` daemon named ``osd.0``, execute the following::
+debug logging for a ``ceph-osd`` daemon named ``osd.0``, execute the following::
ceph osd tell 0 injectargs '--debug-osd 20 --debug-ms 1'
Viewing a Configuration at Runtime
==================================
-If your Ceph cluster is running, and you would like to see the configuration
-settings from a running daemon, execute the following::
+If your Ceph Storage Cluster is running, and you would like to see the
+configuration settings from a running daemon, execute the following::
ceph --admin-daemon {/path/to/admin/socket} config show | less
/var/run/ceph/$cluster-$name.asok
-At real time, the metavariables will evaluate to the actual cluster name
-and daemon name. For example, if the cluster name is ``ceph`` (it is by default)
+At real time, the metavariables will evaluate to the actual cluster name and
+daemon name. For example, if the cluster name is ``ceph`` (it is by default)
and you want to retrieve the configuration for ``osd.0``, use the following::
ceph --admin-daemon /var/run/ceph/ceph-osd.0.asok config show | less
Running Multiple Clusters
=========================
-With Ceph, you can run multiple clusters on the same hardware. Running multiple
-clusters provides a higher level of isolation compared to using different pools
-on the same cluster with different CRUSH rulesets. A separate cluster will have
-separate monitor, OSD and metadata server processes. When running Ceph with
-default settings, the default cluster name is ``ceph``, which means you would
-save your Ceph configuration file with the file name ``ceph.conf`` in the
-``/etc/ceph`` default directory.
+With Ceph, you can run multiple Ceph Storage Clusters on the same hardware.
+Running multiple clusters provides a higher level of isolation compared to
+using different pools on the same cluster with different CRUSH rulesets. A
+separate cluster will have separate monitor, OSD and metadata server processes.
+When running Ceph with default settings, the default cluster name is ``ceph``,
+which means you would save your Ceph configuration file with the file name
+``ceph.conf`` in the ``/etc/ceph`` default directory.
+
+See `ceph-deploy new` for details.
When you run multiple clusters, you must name your cluster and save the Ceph
configuration file with the name of the cluster. For example, a cluster named
.. _hardware recommendations: ../../../install/hardware-recommendations
.. _Network Configuration Reference: ../network-config-ref
.. _OSD Config Reference: ../osd-config-ref
-.. _Configuring Monitor/OSD Interaction: ../mon-osd-interaction
\ No newline at end of file
+.. _Configuring Monitor/OSD Interaction: ../mon-osd-interaction
+.. _ceph-deploy new: ../../deployment/ceph-deploy-new#naming-a-cluster
\ No newline at end of file
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