--- /dev/null
+==================
+ Configuring Ceph
+==================
+
+When you start the Ceph service, the initialization process activates a series
+of daemons that run in the background. A :term:`Ceph Storage Cluster` runs
+two types of daemons:
+
+- :term:`Ceph Monitor` (``ceph-mon``)
+- :term:`Ceph OSD Daemon` (``ceph-osd``)
+
+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.
+
+
+.. _ceph-conf-file:
+
+The Configuration File
+======================
+
+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
+- Cluster membership
+- Host names
+- Host addresses
+- Paths to keyrings
+- Paths to journals
+- Paths to data
+- Other runtime options
+
+The default Ceph configuration file locations in sequential order include:
+
+#. ``$CEPH_CONF`` (*i.e.,* the path following the ``$CEPH_CONF``
+ environment variable)
+#. ``-c path/path`` (*i.e.,* the ``-c`` command line argument)
+#. ``/etc/ceph/ceph.conf``
+#. ``~/.ceph/config``
+#. ``./ceph.conf`` (*i.e.,* in the current working directory)
+
+
+The Ceph configuration file uses an *ini* style syntax. You can add comments
+by preceding comments with a pound sign (#) or a semi-colon (;). For example:
+
+.. code-block:: ini
+
+ # <--A number (#) sign precedes a comment.
+ ; A comment may be anything.
+ # Comments always follow a semi-colon (;) or a pound (#) on each line.
+ # The end of the line terminates a comment.
+ # We recommend that you provide comments in your configuration file(s).
+
+
+.. _ceph-conf-settings:
+
+Config Sections
+===============
+
+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 Storage
+ Cluster.
+
+:Example: ``auth supported = cephx``
+
+``[osd]``
+
+:Description: Settings under ``[osd]`` affect all ``ceph-osd`` daemons in
+ 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 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 Ceph Storage Cluster, and override the same setting in
+ ``[global]``.
+
+:Example: ``host = myserver01``
+
+``[client]``
+
+: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 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]`` ).
+
+#. Changing the setting in a particular process (*e.g.,* ``[osd.1]`` ).
+
+Overriding a global setting affects all child processes, except those that
+you specifically override in a particular daemon.
+
+A typical global setting involves activating authentication. For example:
+
+.. code-block:: ini
+
+ [global]
+ #Enable authentication between hosts within the cluster.
+ #v 0.54 and earlier
+ auth supported = cephx
+
+ #v 0.55 and after
+ auth cluster required = cephx
+ auth service required = cephx
+ auth client required = cephx
+
+
+You can specify settings that apply to a particular type of daemon. When you
+specify settings under ``[osd]``, ``[mon]`` or ``[mds]`` without specifying a
+particular instance, the setting will apply to all OSDs, monitors or metadata
+daemons respectively.
+
+A typical daemon-wide setting involves setting journal sizes, filestore
+settings, etc. For example:
+
+.. code-block:: ini
+
+ [osd]
+ osd journal size = 1000
+
+
+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 a Ceph OSD Daemon is always numeric, but it may be
+alphanumeric for Ceph Monitors and Ceph Metadata Servers.
+
+.. code-block:: ini
+
+ [osd.1]
+ # settings affect osd.1 only.
+
+ [mon.a]
+ # settings affect mon.a only.
+
+ [mds.b]
+ # settings affect mds.b only.
+
+
+If the daemon you specify is a Ceph Gateway client, specify the daemon and the
+instance, delimited by a period (.). For example::
+
+ [client.radosgw.instance-name]
+ # settings affect client.radosgw.instance-name only.
+
+
+
+.. _ceph-metavariables:
+
+Metavariables
+=============
+
+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]``, ``[mds]`` or ``[client]`` sections of your
+configuration file. Ceph metavariables are similar to Bash shell expansion.
+
+Ceph supports the following metavariables:
+
+
+``$cluster``
+
+:Description: Expands to the Ceph Storage Cluster name. Useful when running
+ multiple Ceph Storage Clusters on the same hardware.
+
+:Example: ``/etc/ceph/$cluster.keyring``
+:Default: ``ceph``
+
+
+``$type``
+
+:Description: Expands to one of ``mds``, ``osd``, or ``mon``, depending on the
+ type of the instant daemon.
+
+:Example: ``/var/lib/ceph/$type``
+
+
+``$id``
+
+:Description: Expands to the daemon identifier. For ``osd.0``, this would be
+ ``0``; for ``mds.a``, it would be ``a``.
+
+:Example: ``/var/lib/ceph/$type/$cluster-$id``
+
+
+``$host``
+
+:Description: Expands to the host name of the instant daemon.
+
+
+``$name``
+
+:Description: Expands to ``$type.$id``.
+:Example: ``/var/run/ceph/$cluster-$name.asok``
+
+``$pid``
+
+:Description: Expands to daemon pid.
+:Example: ``/var/run/ceph/$cluster-$name-$pid.asok``
+
+
+.. _ceph-conf-common-settings:
+
+Common Settings
+===============
+
+The `Hardware Recommendations`_ section provides some hardware guidelines for
+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
+may run one ``ceph-osd`` for each drive. 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 monitor daemons. For example:
+
+.. code-block:: ini
+
+ [global]
+ mon_initial_members = ceph1
+ mon_host = 10.0.0.1
+
+
+.. 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 node. Do not use ``host``
+ settings for anything other than initial monitors unless you are deploying
+ Ceph manually. You **MUST NOT** specify ``host`` under individual daemons
+ when using deployment tools like ``chef`` or ``ceph-deploy``, as those tools
+ will enter the appropriate values for you in the cluster map.
+
+
+.. _ceph-network-config:
+
+Networks
+========
+
+See the `Network Configuration Reference`_ for a detailed discussion about
+configuring a network for use with Ceph.
+
+
+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 other monitors may interrupt data service availability.
+
+Ceph Monitors typically listen on port ``6789``. For example:
+
+.. code-block:: ini
+
+ [mon.a]
+ 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::
+
+ /var/lib/ceph/mon/$cluster-$id
+
+You or a deployment tool (e.g., ``ceph-deploy``) must create the corresponding
+directory. With metavariables fully expressed and a cluster named "ceph", the
+foregoing directory would evaluate to::
+
+ /var/lib/ceph/mon/ceph-a
+
+For additional details, see the `Monitor Config Reference`_.
+
+.. _Monitor Config Reference: ../mon-config-ref
+
+
+.. _ceph-osd-config:
+
+
+Authentication
+==============
+
+.. 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. ::
+
+ auth cluster required = cephx
+ auth service required = cephx
+ auth client required = cephx
+
+Additionally, you should enable message signing. See `Cephx Config Reference`_ for details.
+
+.. important:: When upgrading, we recommend expressly disabling authentication
+ first, then perform the upgrade. Once the upgrade is complete, re-enable
+ authentication.
+
+.. _Cephx Config Reference: ../auth-config-ref
+
+
+.. _ceph-monitor-config:
+
+
+OSDs
+====
+
+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. For example:
+
+.. code-block:: ini
+
+ [osd]
+ osd journal size = 10000
+
+ [osd.0]
+ host = {hostname} #manual deployments only.
+
+
+By default, Ceph expects that you will store a Ceph OSD Daemon's data with the
+following path::
+
+ /var/lib/ceph/osd/$cluster-$id
+
+You or a deployment tool (e.g., ``ceph-deploy``) must create the corresponding
+directory. With metavariables fully expressed and a cluster named "ceph", the
+foregoing directory would evaluate to::
+
+ /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.
+
+::
+
+ ssh {osd-host}
+ sudo mkdir /var/lib/ceph/osd/ceph-{osd-number}
+
+The ``osd data`` path ideally leads to a mount point with a hard disk that is
+separate from the hard disk storing and running the operating system and
+daemons. If the OSD is for a disk other than the OS disk, prepare it for
+use with Ceph, and mount it to the directory you just created::
+
+ ssh {new-osd-host}
+ sudo mkfs -t {fstype} /dev/{disk}
+ sudo mount -o user_xattr /dev/{hdd} /var/lib/ceph/osd/ceph-{osd-number}
+
+We recommend using the ``xfs`` file system when running
+:command:`mkfs`. (``btrfs`` and ``ext4`` are not recommended and no
+longer tested.)
+
+See the `OSD Config Reference`_ for additional configuration details.
+
+
+Heartbeats
+==========
+
+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.
+
+
+.. _ceph-logging-and-debugging:
+
+Logs / Debugging
+================
+
+Sometimes you may encounter issues with Ceph that require
+modifying logging output and using Ceph's debugging. See `Debugging and
+Logging`_ for details on log rotation.
+
+.. _Debugging and Logging: ../../troubleshooting/log-and-debug
+
+
+Example ceph.conf
+=================
+
+.. literalinclude:: demo-ceph.conf
+ :language: ini
+
+.. _ceph-runtime-config:
+
+Runtime Changes
+===============
+
+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
+configuration usage::
+
+ ceph tell {daemon-type}.{id or *} injectargs --{name} {value} [--{name} {value}]
+
+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::
+
+ ceph tell osd.0 injectargs --debug-osd 20 --debug-ms 1
+
+In your ``ceph.conf`` file, you may use spaces when specifying a
+setting name. When specifying a setting name on the command line,
+ensure that you use an underscore or hyphen (``_`` or ``-``) between
+terms (e.g., ``debug osd`` becomes ``--debug-osd``).
+
+
+Viewing a Configuration at Runtime
+==================================
+
+If your Ceph Storage Cluster is running, and you would like to see the
+configuration settings from a running daemon, execute the following::
+
+ ceph daemon {daemon-type}.{id} config show | less
+
+If you are on a machine where osd.0 is running, the command would be::
+
+ ceph daemon osd.0 config show | less
+
+Reading Configuration Metadata at Runtime
+=========================================
+
+Information about the available configuration options is available via
+the ``config help`` command:
+
+::
+
+ ceph daemon {daemon-type}.{id} config help | less
+
+
+This metadata is primarily intended to be used when integrating other
+software with Ceph, such as graphical user interfaces. The output is
+a list of JSON objects, for example:
+
+::
+
+ {
+ "name": "mon_host",
+ "type": "std::string",
+ "level": "basic",
+ "desc": "list of hosts or addresses to search for a monitor",
+ "long_desc": "This is a comma, whitespace, or semicolon separated list of IP addresses or hostnames. Hostnames are resolved via DNS and all A or AAAA records are included in the search list.",
+ "default": "",
+ "daemon_default": "",
+ "tags": [],
+ "services": [
+ "common"
+ ],
+ "see_also": [],
+ "enum_values": [],
+ "min": "",
+ "max": ""
+ }
+
+type
+____
+
+The type of the setting, given as a C++ type name.
+
+level
+_____
+
+One of `basic`, `advanced`, `dev`. The `dev` options are not intended
+for use outside of development and testing.
+
+desc
+____
+
+A short description -- this is a sentence fragment suitable for display
+in small spaces like a single line in a list.
+
+long_desc
+_________
+
+A full description of what the setting does, this may be as long as needed.
+
+default
+_______
+
+The default value, if any.
+
+daemon_default
+______________
+
+An alternative default used for daemons (services) as opposed to clients.
+
+tags
+____
+
+A list of strings indicating topics to which this setting relates. Examples
+of tags are `performance` and `networking`.
+
+services
+________
+
+A list of strings indicating which Ceph services the setting relates to, such
+as `osd`, `mds`, `mon`. For settings that are relevant to any Ceph client
+or server, `common` is used.
+
+see_also
+________
+
+A list of strings indicating other configuration options that may also
+be of interest to a user setting this option.
+
+enum_values
+___________
+
+Optional: a list of strings indicating the valid settings.
+
+min, max
+________
+
+Optional: upper and lower (inclusive) bounds on valid settings.
+
+
+
+
+Running Multiple Clusters
+=========================
+
+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.
+.. _ceph-deploy new:../ceph-deploy-new
+
+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
+``openstack`` will have a Ceph configuration file with the file name
+``openstack.conf`` in the ``/etc/ceph`` default directory.
+
+.. important:: Cluster names must consist of letters a-z and digits 0-9 only.
+
+Separate clusters imply separate data disks and journals, which are not shared
+between clusters. Referring to `Metavariables`_, the ``$cluster`` metavariable
+evaluates to the cluster name (i.e., ``openstack`` in the foregoing example).
+Various settings use the ``$cluster`` metavariable, including:
+
+- ``keyring``
+- ``admin socket``
+- ``log file``
+- ``pid file``
+- ``mon data``
+- ``mon cluster log file``
+- ``osd data``
+- ``osd journal``
+- ``mds data``
+- ``rgw data``
+
+See `General Settings`_, `OSD Settings`_, `Monitor Settings`_, `MDS Settings`_,
+`RGW Settings`_ and `Log Settings`_ for relevant path defaults that use the
+``$cluster`` metavariable.
+
+.. _General Settings: ../general-config-ref
+.. _OSD Settings: ../osd-config-ref
+.. _Monitor Settings: ../mon-config-ref
+.. _MDS Settings: ../../../cephfs/mds-config-ref
+.. _RGW Settings: ../../../radosgw/config-ref/
+.. _Log Settings: ../../troubleshooting/log-and-debug
+
+
+When creating default directories or files, you should use the cluster
+name at the appropriate places in the path. For example::
+
+ sudo mkdir /var/lib/ceph/osd/openstack-0
+ sudo mkdir /var/lib/ceph/mon/openstack-a
+
+.. important:: When running monitors on the same host, you should use
+ different ports. By default, monitors use port 6789. If you already
+ have monitors using port 6789, use a different port for your other cluster(s).
+
+To invoke a cluster other than the default ``ceph`` cluster, use the
+``-c {filename}.conf`` option with the ``ceph`` command. For example::
+
+ ceph -c {cluster-name}.conf health
+ ceph -c openstack.conf health
+
+
+.. _Hardware Recommendations: ../../../start/hardware-recommendations
+.. _Network Configuration Reference: ../network-config-ref
+.. _OSD Config Reference: ../osd-config-ref
+.. _Configuring Monitor/OSD Interaction: ../mon-osd-interaction
+.. _ceph-deploy new: ../../deployment/ceph-deploy-new#naming-a-cluster
Code Review / stor4nfv.git / blobdiff