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diff --git a/doc/rados/configuration/common.rst b/doc/rados/configuration/common.rst new file mode 100644 index 00000000..acb5d325 --- /dev/null +++ b/doc/rados/configuration/common.rst @@ -0,0 +1,258 @@ + +.. _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 normally listen on port ``3300`` for the new v2 protocol, and ``6789`` for the old v1 protocol. + +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: + + + +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 rules. 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 `Create a Cluster`_ for details. + +.. _Create a Cluster: ../../deployment/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: + +.. _Metavariables: ../ceph-conf#Metavariables + +- ``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 |