From dd8d91b0ded8be70bec3f40f499d7cf9432c9f23 Mon Sep 17 00:00:00 2001 From: Zac Dover Date: Thu, 13 Jul 2023 18:41:51 +1000 Subject: [PATCH] doc/rados: edit ceph-conf.rst Edit doc/rados/configuration/ceph-conf.rst. Co-authored-by: Anthony D'Atri Signed-off-by: Zac Dover --- doc/rados/configuration/ceph-conf.rst | 95 ++++++++++++++------------- 1 file changed, 48 insertions(+), 47 deletions(-) diff --git a/doc/rados/configuration/ceph-conf.rst b/doc/rados/configuration/ceph-conf.rst index e5d2a37b368f9..070ed59c0a066 100644 --- a/doc/rados/configuration/ceph-conf.rst +++ b/doc/rados/configuration/ceph-conf.rst @@ -4,91 +4,92 @@ Configuring Ceph ================== -When Ceph services start, the initialization process activates a series -of daemons that run in the background. A :term:`Ceph Storage Cluster` runs -at a minimum three types of daemons: +When Ceph services start, the initialization process activates a series of +daemons that run in the background. A :term:`Ceph Storage Cluster` runs at +least three types of daemons: - :term:`Ceph Monitor` (``ceph-mon``) - :term:`Ceph Manager` (``ceph-mgr``) - :term:`Ceph OSD Daemon` (``ceph-osd``) Ceph Storage Clusters that support the :term:`Ceph File System` also run at -least one :term:`Ceph Metadata Server` (``ceph-mds``). Clusters that -support :term:`Ceph Object Storage` run Ceph RADOS Gateway daemons -(``radosgw``) as well. +least one :term:`Ceph Metadata Server` (``ceph-mds``). Clusters that support +:term:`Ceph Object Storage` run Ceph RADOS Gateway daemons (``radosgw``). -Each daemon has a number of configuration options, each of which has a -default value. You may adjust the behavior of the system by changing these -configuration options. Be careful to understand the consequences before +Each daemon has a number of configuration options, each of which has a default +value. You may adjust the behavior of the system by changing these +configuration options. Be careful to understand the consequences before overriding default values, as it is possible to significantly degrade the -performance and stability of your cluster. Also note that default values -sometimes change between releases, so it is best to review the version of -this documentation that aligns with your Ceph release. +performance and stability of your cluster. Note too that default values +sometimes change between releases. For this reason, it is best to review the +version of this documentation that applies to your Ceph release. Option names ============ -All Ceph configuration options have a unique name consisting of words -formed with lower-case characters and connected with underscore -(``_``) characters. +Each of the Ceph configuration options has a unique name that consists of words +formed with lowercase characters and connected with underscore characters +(``_``). -When option names are specified on the command line, either underscore -(``_``) or dash (``-``) characters can be used interchangeable (e.g., +When option names are specified on the command line, underscore (``_``) and +dash (``-``) characters can be used interchangeably (for example, ``--mon-host`` is equivalent to ``--mon_host``). -When option names appear in configuration files, spaces can also be -used in place of underscore or dash. We suggest, though, that for -clarity and convenience you consistently use underscores, as we do +When option names appear in configuration files, spaces can also be used in +place of underscores or dashes. However, for the sake of clarity and +convenience, we suggest that you consistently use underscores, as we do throughout this documentation. Config sources ============== -Each Ceph daemon, process, and library will pull its configuration -from several sources, listed below. Sources later in the list will -override those earlier in the list when both are present. +Each Ceph daemon, process, and library pulls its configuration from one or more +of the several sources listed below. Sources that occur later in the list +override those that occur earlier in the list (when both are present). - the compiled-in default value - the monitor cluster's centralized configuration database - a configuration file stored on the local host - environment variables -- command line arguments -- runtime overrides set by an administrator +- command-line arguments +- runtime overrides that are set by an administrator One of the first things a Ceph process does on startup is parse the -configuration options provided via the command line, environment, and -local configuration file. The process will then contact the monitor -cluster to retrieve configuration stored centrally for the entire -cluster. Once a complete view of the configuration is available, the -daemon or process startup will proceed. +configuration options provided via the command line, via the environment, and +via the local configuration file. Next, the process contacts the monitor +cluster to retrieve centrally-stored configuration for the entire cluster. +After a complete view of the configuration is available, the startup of the +daemon or process will commence. .. _bootstrap-options: Bootstrap options ----------------- -Some configuration options affect the process's ability to contact the -monitors, to authenticate, and to retrieve the cluster-stored configuration. -For this reason, these options might need to be stored locally on the node, and -set by means of a local configuration file. These options include the -following: +Bootstrap options are configuration options that affect the process's ability +to contact the monitors, to authenticate, and to retrieve the cluster-stored +configuration. For this reason, these options might need to be stored locally +on the node, and set by means of a local configuration file. These options +include the following: .. confval:: mon_host .. confval:: mon_host_override - :confval:`mon_dns_srv_name` -- :confval:`mon_data`, :confval:`osd_data`, :confval:`mds_data`, :confval:`mgr_data`, and - similar options that define which local directory the daemon - stores its data in. -- :confval:`keyring`, :confval:`keyfile`, and/or :confval:`key`, which can be used to - specify the authentication credential to use to authenticate with - the monitor. Note that in most cases the default keyring location - is in the data directory specified above. - -In most cases, the default values of these options are suitable. There is one -exception to this: the :confval:`mon_host` option that identifies the addresses -of the cluster's monitors. When DNS is used to identify monitors, a local Ceph -configuration file can be avoided entirely. +- :confval:`mon_data`, :confval:`osd_data`, :confval:`mds_data`, + :confval:`mgr_data`, and similar options that define which local directory + the daemon stores its data in. +- :confval:`keyring`, :confval:`keyfile`, and/or :confval:`key`, which can be + used to specify the authentication credential to use to authenticate with the + monitor. Note that in most cases the default keyring location is in the data + directory specified above. + +In most cases, there is no reason to modify the default values of these +options. However, there is one exception to this: the :confval:`mon_host` +option that identifies the addresses of the cluster's monitors. But when DNS is +used to identify monitors, a local Ceph configuration file can be avoided +entirely. + Skipping monitor config ----------------------- -- 2.39.5