--- /dev/null
+==========================
+ Monitor Config Reference
+==========================
+
+Understanding how to configure a :term:`Ceph Monitor` is an important part of
+building a reliable :term:`Ceph Storage Cluster`. **All Ceph Storage Clusters
+have at least one monitor**. A monitor configuration usually remains fairly
+consistent, but you can add, remove or replace a monitor in a cluster. See
+`Adding/Removing a Monitor`_ and `Add/Remove a Monitor (ceph-deploy)`_ for
+details.
+
+
+.. index:: Ceph Monitor; Paxos
+
+Background
+==========
+
+Ceph Monitors maintain a "master copy" of the :term:`cluster map`, which means a
+:term:`Ceph Client` can determine the location of all Ceph Monitors, Ceph OSD
+Daemons, and Ceph Metadata Servers just by connecting to one Ceph Monitor and
+retrieving a current cluster map. Before Ceph Clients can read from or write to
+Ceph OSD Daemons or Ceph Metadata Servers, they must connect to a Ceph Monitor
+first. With a current copy of the cluster map and the CRUSH algorithm, a Ceph
+Client can compute the location for any object. The ability to compute object
+locations allows a Ceph Client to talk directly to Ceph OSD Daemons, which is a
+very important aspect of Ceph's high scalability and performance. See
+`Scalability and High Availability`_ for additional details.
+
+The primary role of the Ceph Monitor is to maintain a master copy of the cluster
+map. Ceph Monitors also provide authentication and logging services. Ceph
+Monitors write all changes in the monitor services to a single Paxos instance,
+and Paxos writes the changes to a key/value store for strong consistency. Ceph
+Monitors can query the most recent version of the cluster map during sync
+operations. Ceph Monitors leverage the key/value store's snapshots and iterators
+(using leveldb) to perform store-wide synchronization.
+
+.. ditaa::
+
+ /-------------\ /-------------\
+ | Monitor | Write Changes | Paxos |
+ | cCCC +-------------->+ cCCC |
+ | | | |
+ +-------------+ \------+------/
+ | Auth | |
+ +-------------+ | Write Changes
+ | Log | |
+ +-------------+ v
+ | Monitor Map | /------+------\
+ +-------------+ | Key / Value |
+ | OSD Map | | Store |
+ +-------------+ | cCCC |
+ | PG Map | \------+------/
+ +-------------+ ^
+ | MDS Map | | Read Changes
+ +-------------+ |
+ | cCCC |*---------------------+
+ \-------------/
+
+
+.. deprecated:: version 0.58
+
+In Ceph versions 0.58 and earlier, Ceph Monitors use a Paxos instance for
+each service and store the map as a file.
+
+.. index:: Ceph Monitor; cluster map
+
+Cluster Maps
+------------
+
+The cluster map is a composite of maps, including the monitor map, the OSD map,
+the placement group map and the metadata server map. The cluster map tracks a
+number of important things: which processes are ``in`` the Ceph Storage Cluster;
+which processes that are ``in`` the Ceph Storage Cluster are ``up`` and running
+or ``down``; whether, the placement groups are ``active`` or ``inactive``, and
+``clean`` or in some other state; and, other details that reflect the current
+state of the cluster such as the total amount of storage space, and the amount
+of storage used.
+
+When there is a significant change in the state of the cluster--e.g., a Ceph OSD
+Daemon goes down, a placement group falls into a degraded state, etc.--the
+cluster map gets updated to reflect the current state of the cluster.
+Additionally, the Ceph Monitor also maintains a history of the prior states of
+the cluster. The monitor map, OSD map, placement group map and metadata server
+map each maintain a history of their map versions. We call each version an
+"epoch."
+
+When operating your Ceph Storage Cluster, keeping track of these states is an
+important part of your system administration duties. See `Monitoring a Cluster`_
+and `Monitoring OSDs and PGs`_ for additional details.
+
+.. index:: high availability; quorum
+
+Monitor Quorum
+--------------
+
+Our Configuring ceph section provides a trivial `Ceph configuration file`_ that
+provides for one monitor in the test cluster. A cluster will run fine with a
+single monitor; however, **a single monitor is a single-point-of-failure**. To
+ensure high availability in a production Ceph Storage Cluster, you should run
+Ceph with multiple monitors so that the failure of a single monitor **WILL NOT**
+bring down your entire cluster.
+
+When a Ceph Storage Cluster runs multiple Ceph Monitors for high availability,
+Ceph Monitors use `Paxos`_ to establish consensus about the master cluster map.
+A consensus requires a majority of monitors running to establish a quorum for
+consensus about the cluster map (e.g., 1; 2 out of 3; 3 out of 5; 4 out of 6;
+etc.).
+
+``mon force quorum join``
+
+:Description: Force monitor to join quorum even if it has been previously removed from the map
+:Type: Boolean
+:Default: ``False``
+
+.. index:: Ceph Monitor; consistency
+
+Consistency
+-----------
+
+When you add monitor settings to your Ceph configuration file, you need to be
+aware of some of the architectural aspects of Ceph Monitors. **Ceph imposes
+strict consistency requirements** for a Ceph monitor when discovering another
+Ceph Monitor within the cluster. Whereas, Ceph Clients and other Ceph daemons
+use the Ceph configuration file to discover monitors, monitors discover each
+other using the monitor map (monmap), not the Ceph configuration file.
+
+A Ceph Monitor always refers to the local copy of the monmap when discovering
+other Ceph Monitors in the Ceph Storage Cluster. Using the monmap instead of the
+Ceph configuration file avoids errors that could break the cluster (e.g., typos
+in ``ceph.conf`` when specifying a monitor address or port). Since monitors use
+monmaps for discovery and they share monmaps with clients and other Ceph
+daemons, **the monmap provides monitors with a strict guarantee that their
+consensus is valid.**
+
+Strict consistency also applies to updates to the monmap. As with any other
+updates on the Ceph Monitor, changes to the monmap always run through a
+distributed consensus algorithm called `Paxos`_. The Ceph Monitors must agree on
+each update to the monmap, such as adding or removing a Ceph Monitor, to ensure
+that each monitor in the quorum has the same version of the monmap. Updates to
+the monmap are incremental so that Ceph Monitors have the latest agreed upon
+version, and a set of previous versions. Maintaining a history enables a Ceph
+Monitor that has an older version of the monmap to catch up with the current
+state of the Ceph Storage Cluster.
+
+If Ceph Monitors discovered each other through the Ceph configuration file
+instead of through the monmap, it would introduce additional risks because the
+Ceph configuration files are not updated and distributed automatically. Ceph
+Monitors might inadvertently use an older Ceph configuration file, fail to
+recognize a Ceph Monitor, fall out of a quorum, or develop a situation where
+`Paxos`_ is not able to determine the current state of the system accurately.
+
+
+.. index:: Ceph Monitor; bootstrapping monitors
+
+Bootstrapping Monitors
+----------------------
+
+In most configuration and deployment cases, tools that deploy Ceph may help
+bootstrap the Ceph Monitors by generating a monitor map for you (e.g.,
+``ceph-deploy``, etc). A Ceph Monitor requires a few explicit
+settings:
+
+- **Filesystem ID**: The ``fsid`` is the unique identifier for your
+ object store. Since you can run multiple clusters on the same
+ hardware, you must specify the unique ID of the object store when
+ bootstrapping a monitor. Deployment tools usually do this for you
+ (e.g., ``ceph-deploy`` can call a tool like ``uuidgen``), but you
+ may specify the ``fsid`` manually too.
+
+- **Monitor ID**: A monitor ID is a unique ID assigned to each monitor within
+ the cluster. It is an alphanumeric value, and by convention the identifier
+ usually follows an alphabetical increment (e.g., ``a``, ``b``, etc.). This
+ can be set in a Ceph configuration file (e.g., ``[mon.a]``, ``[mon.b]``, etc.),
+ by a deployment tool, or using the ``ceph`` commandline.
+
+- **Keys**: The monitor must have secret keys. A deployment tool such as
+ ``ceph-deploy`` usually does this for you, but you may
+ perform this step manually too. See `Monitor Keyrings`_ for details.
+
+For additional details on bootstrapping, see `Bootstrapping a Monitor`_.
+
+.. index:: Ceph Monitor; configuring monitors
+
+Configuring Monitors
+====================
+
+To apply configuration settings to the entire cluster, enter the configuration
+settings under ``[global]``. To apply configuration settings to all monitors in
+your cluster, enter the configuration settings under ``[mon]``. To apply
+configuration settings to specific monitors, specify the monitor instance
+(e.g., ``[mon.a]``). By convention, monitor instance names use alpha notation.
+
+.. code-block:: ini
+
+ [global]
+
+ [mon]
+
+ [mon.a]
+
+ [mon.b]
+
+ [mon.c]
+
+
+Minimum Configuration
+---------------------
+
+The bare minimum monitor settings for a Ceph monitor via the Ceph configuration
+file include a hostname and a monitor address for each monitor. You can configure
+these under ``[mon]`` or under the entry for a specific monitor.
+
+.. code-block:: ini
+
+ [mon]
+ mon host = hostname1,hostname2,hostname3
+ mon addr = 10.0.0.10:6789,10.0.0.11:6789,10.0.0.12:6789
+
+
+.. code-block:: ini
+
+ [mon.a]
+ host = hostname1
+ mon addr = 10.0.0.10:6789
+
+See the `Network Configuration Reference`_ for details.
+
+.. note:: This minimum configuration for monitors assumes that a deployment
+ tool generates the ``fsid`` and the ``mon.`` key for you.
+
+Once you deploy a Ceph cluster, you **SHOULD NOT** change the IP address of
+the monitors. However, if you decide to change the monitor's IP address, you
+must follow a specific procedure. See `Changing a Monitor's IP Address`_ for
+details.
+
+Monitors can also be found by clients using DNS SRV records. See `Monitor lookup through DNS`_ for details.
+
+Cluster ID
+----------
+
+Each Ceph Storage Cluster has a unique identifier (``fsid``). If specified, it
+usually appears under the ``[global]`` section of the configuration file.
+Deployment tools usually generate the ``fsid`` and store it in the monitor map,
+so the value may not appear in a configuration file. The ``fsid`` makes it
+possible to run daemons for multiple clusters on the same hardware.
+
+``fsid``
+
+:Description: The cluster ID. One per cluster.
+:Type: UUID
+:Required: Yes.
+:Default: N/A. May be generated by a deployment tool if not specified.
+
+.. note:: Do not set this value if you use a deployment tool that does
+ it for you.
+
+
+.. index:: Ceph Monitor; initial members
+
+Initial Members
+---------------
+
+We recommend running a production Ceph Storage Cluster with at least three Ceph
+Monitors to ensure high availability. When you run multiple monitors, you may
+specify the initial monitors that must be members of the cluster in order to
+establish a quorum. This may reduce the time it takes for your cluster to come
+online.
+
+.. code-block:: ini
+
+ [mon]
+ mon initial members = a,b,c
+
+
+``mon initial members``
+
+:Description: The IDs of initial monitors in a cluster during startup. If
+ specified, Ceph requires an odd number of monitors to form an
+ initial quorum (e.g., 3).
+
+:Type: String
+:Default: None
+
+.. note:: A *majority* of monitors in your cluster must be able to reach
+ each other in order to establish a quorum. You can decrease the initial
+ number of monitors to establish a quorum with this setting.
+
+.. index:: Ceph Monitor; data path
+
+Data
+----
+
+Ceph provides a default path where Ceph Monitors store data. For optimal
+performance in a production Ceph Storage Cluster, we recommend running Ceph
+Monitors on separate hosts and drives from Ceph OSD Daemons. As leveldb is using
+``mmap()`` for writing the data, Ceph Monitors flush their data from memory to disk
+very often, which can interfere with Ceph OSD Daemon workloads if the data
+store is co-located with the OSD Daemons.
+
+In Ceph versions 0.58 and earlier, Ceph Monitors store their data in files. This
+approach allows users to inspect monitor data with common tools like ``ls``
+and ``cat``. However, it doesn't provide strong consistency.
+
+In Ceph versions 0.59 and later, Ceph Monitors store their data as key/value
+pairs. Ceph Monitors require `ACID`_ transactions. Using a data store prevents
+recovering Ceph Monitors from running corrupted versions through Paxos, and it
+enables multiple modification operations in one single atomic batch, among other
+advantages.
+
+Generally, we do not recommend changing the default data location. If you modify
+the default location, we recommend that you make it uniform across Ceph Monitors
+by setting it in the ``[mon]`` section of the configuration file.
+
+
+``mon data``
+
+:Description: The monitor's data location.
+:Type: String
+:Default: ``/var/lib/ceph/mon/$cluster-$id``
+
+
+``mon data size warn``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log when the monitor's data
+ store goes over 15GB.
+:Type: Integer
+:Default: 15*1024*1024*1024*
+
+
+``mon data avail warn``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log when the available disk
+ space of monitor's data store is lower or equal to this
+ percentage.
+:Type: Integer
+:Default: 30
+
+
+``mon data avail crit``
+
+:Description: Issue a ``HEALTH_ERR`` in cluster log when the available disk
+ space of monitor's data store is lower or equal to this
+ percentage.
+:Type: Integer
+:Default: 5
+
+
+``mon warn on cache pools without hit sets``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log if a cache pool does not
+ have the hitset type set set.
+ See `hit set type <../operations/pools#hit-set-type>`_ for more
+ details.
+:Type: Boolean
+:Default: True
+
+
+``mon warn on crush straw calc version zero``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log if the CRUSH's
+ ``straw_calc_version`` is zero. See
+ `CRUSH map tunables <../operations/crush-map#tunables>`_ for
+ details.
+:Type: Boolean
+:Default: True
+
+
+``mon warn on legacy crush tunables``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log if
+ CRUSH tunables are too old (older than ``mon_min_crush_required_version``)
+:Type: Boolean
+:Default: True
+
+
+``mon crush min required version``
+
+:Description: The minimum tunable profile version required by the cluster.
+ See
+ `CRUSH map tunables <../operations/crush-map#tunables>`_ for
+ details.
+:Type: String
+:Default: ``firefly``
+
+
+``mon warn on osd down out interval zero``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log if
+ ``mon osd down out interval`` is zero. Having this option set to
+ zero on the leader acts much like the ``noout`` flag. It's hard
+ to figure out what's going wrong with clusters witout the
+ ``noout`` flag set but acting like that just the same, so we
+ report a warning in this case.
+:Type: Boolean
+:Default: True
+
+
+``mon cache target full warn ratio``
+
+:Description: Position between pool's ``cache_target_full`` and
+ ``target_max_object`` where we start warning
+:Type: Float
+:Default: ``0.66``
+
+
+``mon health data update interval``
+
+:Description: How often (in seconds) the monitor in quorum shares its health
+ status with its peers. (negative number disables it)
+:Type: Float
+:Default: ``60``
+
+
+``mon health to clog``
+
+:Description: Enable sending health summary to cluster log periodically.
+:Type: Boolean
+:Default: True
+
+
+``mon health to clog tick interval``
+
+:Description: How often (in seconds) the monitor send health summary to cluster
+ log (a non-positive number disables it). If current health summary
+ is empty or identical to the last time, monitor will not send it
+ to cluster log.
+:Type: Integer
+:Default: 3600
+
+
+``mon health to clog interval``
+
+:Description: How often (in seconds) the monitor send health summary to cluster
+ log (a non-positive number disables it). Monitor will always
+ send the summary to cluster log no matter if the summary changes
+ or not.
+:Type: Integer
+:Default: 60
+
+
+
+.. index:: Ceph Storage Cluster; capacity planning, Ceph Monitor; capacity planning
+
+Storage Capacity
+----------------
+
+When a Ceph Storage Cluster gets close to its maximum capacity (i.e., ``mon osd
+full ratio``), Ceph prevents you from writing to or reading from Ceph OSD
+Daemons as a safety measure to prevent data loss. Therefore, letting a
+production Ceph Storage Cluster approach its full ratio is not a good practice,
+because it sacrifices high availability. The default full ratio is ``.95``, or
+95% of capacity. This a very aggressive setting for a test cluster with a small
+number of OSDs.
+
+.. tip:: When monitoring your cluster, be alert to warnings related to the
+ ``nearfull`` ratio. This means that a failure of some OSDs could result
+ in a temporary service disruption if one or more OSDs fails. Consider adding
+ more OSDs to increase storage capacity.
+
+A common scenario for test clusters involves a system administrator removing a
+Ceph OSD Daemon from the Ceph Storage Cluster to watch the cluster rebalance;
+then, removing another Ceph OSD Daemon, and so on until the Ceph Storage Cluster
+eventually reaches the full ratio and locks up. We recommend a bit of capacity
+planning even with a test cluster. Planning enables you to gauge how much spare
+capacity you will need in order to maintain high availability. Ideally, you want
+to plan for a series of Ceph OSD Daemon failures where the cluster can recover
+to an ``active + clean`` state without replacing those Ceph OSD Daemons
+immediately. You can run a cluster in an ``active + degraded`` state, but this
+is not ideal for normal operating conditions.
+
+The following diagram depicts a simplistic Ceph Storage Cluster containing 33
+Ceph Nodes with one Ceph OSD Daemon per host, each Ceph OSD Daemon reading from
+and writing to a 3TB drive. So this exemplary Ceph Storage Cluster has a maximum
+actual capacity of 99TB. With a ``mon osd full ratio`` of ``0.95``, if the Ceph
+Storage Cluster falls to 5TB of remaining capacity, the cluster will not allow
+Ceph Clients to read and write data. So the Ceph Storage Cluster's operating
+capacity is 95TB, not 99TB.
+
+.. ditaa::
+
+ +--------+ +--------+ +--------+ +--------+ +--------+ +--------+
+ | Rack 1 | | Rack 2 | | Rack 3 | | Rack 4 | | Rack 5 | | Rack 6 |
+ | cCCC | | cF00 | | cCCC | | cCCC | | cCCC | | cCCC |
+ +--------+ +--------+ +--------+ +--------+ +--------+ +--------+
+ | OSD 1 | | OSD 7 | | OSD 13 | | OSD 19 | | OSD 25 | | OSD 31 |
+ +--------+ +--------+ +--------+ +--------+ +--------+ +--------+
+ | OSD 2 | | OSD 8 | | OSD 14 | | OSD 20 | | OSD 26 | | OSD 32 |
+ +--------+ +--------+ +--------+ +--------+ +--------+ +--------+
+ | OSD 3 | | OSD 9 | | OSD 15 | | OSD 21 | | OSD 27 | | OSD 33 |
+ +--------+ +--------+ +--------+ +--------+ +--------+ +--------+
+ | OSD 4 | | OSD 10 | | OSD 16 | | OSD 22 | | OSD 28 | | Spare |
+ +--------+ +--------+ +--------+ +--------+ +--------+ +--------+
+ | OSD 5 | | OSD 11 | | OSD 17 | | OSD 23 | | OSD 29 | | Spare |
+ +--------+ +--------+ +--------+ +--------+ +--------+ +--------+
+ | OSD 6 | | OSD 12 | | OSD 18 | | OSD 24 | | OSD 30 | | Spare |
+ +--------+ +--------+ +--------+ +--------+ +--------+ +--------+
+
+It is normal in such a cluster for one or two OSDs to fail. A less frequent but
+reasonable scenario involves a rack's router or power supply failing, which
+brings down multiple OSDs simultaneously (e.g., OSDs 7-12). In such a scenario,
+you should still strive for a cluster that can remain operational and achieve an
+``active + clean`` state--even if that means adding a few hosts with additional
+OSDs in short order. If your capacity utilization is too high, you may not lose
+data, but you could still sacrifice data availability while resolving an outage
+within a failure domain if capacity utilization of the cluster exceeds the full
+ratio. For this reason, we recommend at least some rough capacity planning.
+
+Identify two numbers for your cluster:
+
+#. The number of OSDs.
+#. The total capacity of the cluster
+
+If you divide the total capacity of your cluster by the number of OSDs in your
+cluster, you will find the mean average capacity of an OSD within your cluster.
+Consider multiplying that number by the number of OSDs you expect will fail
+simultaneously during normal operations (a relatively small number). Finally
+multiply the capacity of the cluster by the full ratio to arrive at a maximum
+operating capacity; then, subtract the number of amount of data from the OSDs
+you expect to fail to arrive at a reasonable full ratio. Repeat the foregoing
+process with a higher number of OSD failures (e.g., a rack of OSDs) to arrive at
+a reasonable number for a near full ratio.
+
+.. code-block:: ini
+
+ [global]
+
+ mon osd full ratio = .80
+ mon osd backfillfull ratio = .75
+ mon osd nearfull ratio = .70
+
+
+``mon osd full ratio``
+
+:Description: The percentage of disk space used before an OSD is
+ considered ``full``.
+
+:Type: Float
+:Default: ``.95``
+
+
+``mon osd backfillfull ratio``
+
+:Description: The percentage of disk space used before an OSD is
+ considered too ``full`` to backfill.
+
+:Type: Float
+:Default: ``.90``
+
+
+``mon osd nearfull ratio``
+
+:Description: The percentage of disk space used before an OSD is
+ considered ``nearfull``.
+
+:Type: Float
+:Default: ``.85``
+
+
+.. tip:: If some OSDs are nearfull, but others have plenty of capacity, you
+ may have a problem with the CRUSH weight for the nearfull OSDs.
+
+.. index:: heartbeat
+
+Heartbeat
+---------
+
+Ceph monitors know about the cluster by requiring reports from each OSD, and by
+receiving reports from OSDs about the status of their neighboring OSDs. Ceph
+provides reasonable default settings for monitor/OSD interaction; however, you
+may modify them as needed. See `Monitor/OSD Interaction`_ for details.
+
+
+.. index:: Ceph Monitor; leader, Ceph Monitor; provider, Ceph Monitor; requester, Ceph Monitor; synchronization
+
+Monitor Store Synchronization
+-----------------------------
+
+When you run a production cluster with multiple monitors (recommended), each
+monitor checks to see if a neighboring monitor has a more recent version of the
+cluster map (e.g., a map in a neighboring monitor with one or more epoch numbers
+higher than the most current epoch in the map of the instant monitor).
+Periodically, one monitor in the cluster may fall behind the other monitors to
+the point where it must leave the quorum, synchronize to retrieve the most
+current information about the cluster, and then rejoin the quorum. For the
+purposes of synchronization, monitors may assume one of three roles:
+
+#. **Leader**: The `Leader` is the first monitor to achieve the most recent
+ Paxos version of the cluster map.
+
+#. **Provider**: The `Provider` is a monitor that has the most recent version
+ of the cluster map, but wasn't the first to achieve the most recent version.
+
+#. **Requester:** A `Requester` is a monitor that has fallen behind the leader
+ and must synchronize in order to retrieve the most recent information about
+ the cluster before it can rejoin the quorum.
+
+These roles enable a leader to delegate synchronization duties to a provider,
+which prevents synchronization requests from overloading the leader--improving
+performance. In the following diagram, the requester has learned that it has
+fallen behind the other monitors. The requester asks the leader to synchronize,
+and the leader tells the requester to synchronize with a provider.
+
+
+.. ditaa:: +-----------+ +---------+ +----------+
+ | Requester | | Leader | | Provider |
+ +-----------+ +---------+ +----------+
+ | | |
+ | | |
+ | Ask to Synchronize | |
+ |------------------->| |
+ | | |
+ |<-------------------| |
+ | Tell Requester to | |
+ | Sync with Provider | |
+ | | |
+ | Synchronize |
+ |--------------------+-------------------->|
+ | | |
+ |<-------------------+---------------------|
+ | Send Chunk to Requester |
+ | (repeat as necessary) |
+ | Requester Acks Chuck to Provider |
+ |--------------------+-------------------->|
+ | |
+ | Sync Complete |
+ | Notification |
+ |------------------->|
+ | |
+ |<-------------------|
+ | Ack |
+ | |
+
+
+Synchronization always occurs when a new monitor joins the cluster. During
+runtime operations, monitors may receive updates to the cluster map at different
+times. This means the leader and provider roles may migrate from one monitor to
+another. If this happens while synchronizing (e.g., a provider falls behind the
+leader), the provider can terminate synchronization with a requester.
+
+Once synchronization is complete, Ceph requires trimming across the cluster.
+Trimming requires that the placement groups are ``active + clean``.
+
+
+``mon sync trim timeout``
+
+:Description:
+:Type: Double
+:Default: ``30.0``
+
+
+``mon sync heartbeat timeout``
+
+:Description:
+:Type: Double
+:Default: ``30.0``
+
+
+``mon sync heartbeat interval``
+
+:Description:
+:Type: Double
+:Default: ``5.0``
+
+
+``mon sync backoff timeout``
+
+:Description:
+:Type: Double
+:Default: ``30.0``
+
+
+``mon sync timeout``
+
+:Description: Number of seconds the monitor will wait for the next update
+ message from its sync provider before it gives up and bootstrap
+ again.
+:Type: Double
+:Default: ``30.0``
+
+
+``mon sync max retries``
+
+:Description:
+:Type: Integer
+:Default: ``5``
+
+
+``mon sync max payload size``
+
+:Description: The maximum size for a sync payload (in bytes).
+:Type: 32-bit Integer
+:Default: ``1045676``
+
+
+``paxos max join drift``
+
+:Description: The maximum Paxos iterations before we must first sync the
+ monitor data stores. When a monitor finds that its peer is too
+ far ahead of it, it will first sync with data stores before moving
+ on.
+:Type: Integer
+:Default: ``10``
+
+``paxos stash full interval``
+
+:Description: How often (in commits) to stash a full copy of the PaxosService state.
+ Current this setting only affects ``mds``, ``mon``, ``auth`` and ``mgr``
+ PaxosServices.
+:Type: Integer
+:Default: 25
+
+``paxos propose interval``
+
+:Description: Gather updates for this time interval before proposing
+ a map update.
+:Type: Double
+:Default: ``1.0``
+
+
+``paxos min``
+
+:Description: The minimum number of paxos states to keep around
+:Type: Integer
+:Default: 500
+
+
+``paxos min wait``
+
+:Description: The minimum amount of time to gather updates after a period of
+ inactivity.
+:Type: Double
+:Default: ``0.05``
+
+
+``paxos trim min``
+
+:Description: Number of extra proposals tolerated before trimming
+:Type: Integer
+:Default: 250
+
+
+``paxos trim max``
+
+:Description: The maximum number of extra proposals to trim at a time
+:Type: Integer
+:Default: 500
+
+
+``paxos service trim min``
+
+:Description: The minimum amount of versions to trigger a trim (0 disables it)
+:Type: Integer
+:Default: 250
+
+
+``paxos service trim max``
+
+:Description: The maximum amount of versions to trim during a single proposal (0 disables it)
+:Type: Integer
+:Default: 500
+
+
+``mon max log epochs``
+
+:Description: The maximum amount of log epochs to trim during a single proposal
+:Type: Integer
+:Default: 500
+
+
+``mon max pgmap epochs``
+
+:Description: The maximum amount of pgmap epochs to trim during a single proposal
+:Type: Integer
+:Default: 500
+
+
+``mon mds force trim to``
+
+:Description: Force monitor to trim mdsmaps to this point (0 disables it.
+ dangerous, use with care)
+:Type: Integer
+:Default: 0
+
+
+``mon osd force trim to``
+
+:Description: Force monitor to trim osdmaps to this point, even if there is
+ PGs not clean at the specified epoch (0 disables it. dangerous,
+ use with care)
+:Type: Integer
+:Default: 0
+
+``mon osd cache size``
+
+:Description: The size of osdmaps cache, not to rely on underlying store's cache
+:Type: Integer
+:Default: 10
+
+
+``mon election timeout``
+
+:Description: On election proposer, maximum waiting time for all ACKs in seconds.
+:Type: Float
+:Default: ``5``
+
+
+``mon lease``
+
+:Description: The length (in seconds) of the lease on the monitor's versions.
+:Type: Float
+:Default: ``5``
+
+
+``mon lease renew interval factor``
+
+:Description: ``mon lease`` \* ``mon lease renew interval factor`` will be the
+ interval for the Leader to renew the other monitor's leases. The
+ factor should be less than ``1.0``.
+:Type: Float
+:Default: ``0.6``
+
+
+``mon lease ack timeout factor``
+
+:Description: The Leader will wait ``mon lease`` \* ``mon lease ack timeout factor``
+ for the Providers to acknowledge the lease extension.
+:Type: Float
+:Default: ``2.0``
+
+
+``mon accept timeout factor``
+
+:Description: The Leader will wait ``mon lease`` \* ``mon accept timeout factor``
+ for the Requester(s) to accept a Paxos update. It is also used
+ during the Paxos recovery phase for similar purposes.
+:Type: Float
+:Default: ``2.0``
+
+
+``mon min osdmap epochs``
+
+:Description: Minimum number of OSD map epochs to keep at all times.
+:Type: 32-bit Integer
+:Default: ``500``
+
+
+``mon max pgmap epochs``
+
+:Description: Maximum number of PG map epochs the monitor should keep.
+:Type: 32-bit Integer
+:Default: ``500``
+
+
+``mon max log epochs``
+
+:Description: Maximum number of Log epochs the monitor should keep.
+:Type: 32-bit Integer
+:Default: ``500``
+
+
+
+.. index:: Ceph Monitor; clock
+
+Clock
+-----
+
+Ceph daemons pass critical messages to each other, which must be processed
+before daemons reach a timeout threshold. If the clocks in Ceph monitors
+are not synchronized, it can lead to a number of anomalies. For example:
+
+- Daemons ignoring received messages (e.g., timestamps outdated)
+- Timeouts triggered too soon/late when a message wasn't received in time.
+
+See `Monitor Store Synchronization`_ for details.
+
+
+.. tip:: You SHOULD install NTP on your Ceph monitor hosts to
+ ensure that the monitor cluster operates with synchronized clocks.
+
+Clock drift may still be noticeable with NTP even though the discrepancy is not
+yet harmful. Ceph's clock drift / clock skew warnings may get triggered even
+though NTP maintains a reasonable level of synchronization. Increasing your
+clock drift may be tolerable under such circumstances; however, a number of
+factors such as workload, network latency, configuring overrides to default
+timeouts and the `Monitor Store Synchronization`_ settings may influence
+the level of acceptable clock drift without compromising Paxos guarantees.
+
+Ceph provides the following tunable options to allow you to find
+acceptable values.
+
+
+``clock offset``
+
+:Description: How much to offset the system clock. See ``Clock.cc`` for details.
+:Type: Double
+:Default: ``0``
+
+
+.. deprecated:: 0.58
+
+``mon tick interval``
+
+:Description: A monitor's tick interval in seconds.
+:Type: 32-bit Integer
+:Default: ``5``
+
+
+``mon clock drift allowed``
+
+:Description: The clock drift in seconds allowed between monitors.
+:Type: Float
+:Default: ``.050``
+
+
+``mon clock drift warn backoff``
+
+:Description: Exponential backoff for clock drift warnings
+:Type: Float
+:Default: ``5``
+
+
+``mon timecheck interval``
+
+:Description: The time check interval (clock drift check) in seconds
+ for the Leader.
+
+:Type: Float
+:Default: ``300.0``
+
+
+``mon timecheck skew interval``
+
+:Description: The time check interval (clock drift check) in seconds when in
+ presence of a skew in seconds for the Leader.
+:Type: Float
+:Default: ``30.0``
+
+
+Client
+------
+
+``mon client hunt interval``
+
+:Description: The client will try a new monitor every ``N`` seconds until it
+ establishes a connection.
+
+:Type: Double
+:Default: ``3.0``
+
+
+``mon client ping interval``
+
+:Description: The client will ping the monitor every ``N`` seconds.
+:Type: Double
+:Default: ``10.0``
+
+
+``mon client max log entries per message``
+
+:Description: The maximum number of log entries a monitor will generate
+ per client message.
+
+:Type: Integer
+:Default: ``1000``
+
+
+``mon client bytes``
+
+:Description: The amount of client message data allowed in memory (in bytes).
+:Type: 64-bit Integer Unsigned
+:Default: ``100ul << 20``
+
+
+Pool settings
+=============
+Since version v0.94 there is support for pool flags which allow or disallow changes to be made to pools.
+
+Monitors can also disallow removal of pools if configured that way.
+
+``mon allow pool delete``
+
+:Description: If the monitors should allow pools to be removed. Regardless of what the pool flags say.
+:Type: Boolean
+:Default: ``false``
+
+``osd pool default flag hashpspool``
+
+:Description: Set the hashpspool flag on new pools
+:Type: Boolean
+:Default: ``true``
+
+``osd pool default flag nodelete``
+
+:Description: Set the nodelete flag on new pools. Prevents allow pool removal with this flag in any way.
+:Type: Boolean
+:Default: ``false``
+
+``osd pool default flag nopgchange``
+
+:Description: Set the nopgchange flag on new pools. Does not allow the number of PGs to be changed for a pool.
+:Type: Boolean
+:Default: ``false``
+
+``osd pool default flag nosizechange``
+
+:Description: Set the nosizechange flag on new pools. Does not allow the size to be changed of pool.
+:Type: Boolean
+:Default: ``false``
+
+For more information about the pool flags see `Pool values`_.
+
+Miscellaneous
+=============
+
+
+``mon max osd``
+
+:Description: The maximum number of OSDs allowed in the cluster.
+:Type: 32-bit Integer
+:Default: ``10000``
+
+``mon globalid prealloc``
+
+:Description: The number of global IDs to pre-allocate for clients and daemons in the cluster.
+:Type: 32-bit Integer
+:Default: ``100``
+
+``mon subscribe interval``
+
+:Description: The refresh interval (in seconds) for subscriptions. The
+ subscription mechanism enables obtaining the cluster maps
+ and log information.
+
+:Type: Double
+:Default: ``300``
+
+
+``mon stat smooth intervals``
+
+:Description: Ceph will smooth statistics over the last ``N`` PG maps.
+:Type: Integer
+:Default: ``2``
+
+
+``mon probe timeout``
+
+:Description: Number of seconds the monitor will wait to find peers before bootstrapping.
+:Type: Double
+:Default: ``2.0``
+
+
+``mon daemon bytes``
+
+:Description: The message memory cap for metadata server and OSD messages (in bytes).
+:Type: 64-bit Integer Unsigned
+:Default: ``400ul << 20``
+
+
+``mon max log entries per event``
+
+:Description: The maximum number of log entries per event.
+:Type: Integer
+:Default: ``4096``
+
+
+``mon osd prime pg temp``
+
+:Description: Enables or disable priming the PGMap with the previous OSDs when an out
+ OSD comes back into the cluster. With the ``true`` setting the clients
+ will continue to use the previous OSDs until the newly in OSDs as that
+ PG peered.
+:Type: Boolean
+:Default: ``true``
+
+
+``mon osd prime pg temp max time``
+
+:Description: How much time in seconds the monitor should spend trying to prime the
+ PGMap when an out OSD comes back into the cluster.
+:Type: Float
+:Default: ``0.5``
+
+
+``mon osd prime pg temp max time estimate``
+
+:Description: Maximum estimate of time spent on each PG before we prime all PGs
+ in parallel.
+:Type: Float
+:Default: ``0.25``
+
+
+``mon osd allow primary affinity``
+
+:Description: allow ``primary_affinity`` to be set in the osdmap.
+:Type: Boolean
+:Default: False
+
+
+``mon osd pool ec fast read``
+
+:Description: Whether turn on fast read on the pool or not. It will be used as
+ the default setting of newly created erasure pools if ``fast_read``
+ is not specified at create time.
+:Type: Boolean
+:Default: False
+
+
+``mon mds skip sanity``
+
+:Description: Skip safety assertions on FSMap (in case of bugs where we want to
+ continue anyway). Monitor terminates if the FSMap sanity check
+ fails, but we can disable it by enabling this option.
+:Type: Boolean
+:Default: False
+
+
+``mon max mdsmap epochs``
+
+:Description: The maximum amount of mdsmap epochs to trim during a single proposal.
+:Type: Integer
+:Default: 500
+
+
+``mon config key max entry size``
+
+:Description: The maximum size of config-key entry (in bytes)
+:Type: Integer
+:Default: 4096
+
+
+``mon scrub interval``
+
+:Description: How often (in seconds) the monitor scrub its store by comparing
+ the stored checksums with the computed ones of all the stored
+ keys.
+:Type: Integer
+:Default: 3600*24
+
+
+``mon scrub max keys``
+
+:Description: The maximum number of keys to scrub each time.
+:Type: Integer
+:Default: 100
+
+
+``mon compact on start``
+
+:Description: Compact the database used as Ceph Monitor store on
+ ``ceph-mon`` start. A manual compaction helps to shrink the
+ monitor database and improve the performance of it if the regular
+ compaction fails to work.
+:Type: Boolean
+:Default: False
+
+
+``mon compact on bootstrap``
+
+:Description: Compact the database used as Ceph Monitor store on
+ on bootstrap. Monitor starts probing each other for creating
+ a quorum after bootstrap. If it times out before joining the
+ quorum, it will start over and bootstrap itself again.
+:Type: Boolean
+:Default: False
+
+
+``mon compact on trim``
+
+:Description: Compact a certain prefix (including paxos) when we trim its old states.
+:Type: Boolean
+:Default: True
+
+
+``mon cpu threads``
+
+:Description: Number of threads for performing CPU intensive work on monitor.
+:Type: Boolean
+:Default: True
+
+
+``mon osd mapping pgs per chunk``
+
+:Description: We calculate the mapping from placement group to OSDs in chunks.
+ This option specifies the number of placement groups per chunk.
+:Type: Integer
+:Default: 4096
+
+
+``mon osd max split count``
+
+:Description: Largest number of PGs per "involved" OSD to let split create.
+ When we increase the ``pg_num`` of a pool, the placement groups
+ will be splitted on all OSDs serving that pool. We want to avoid
+ extreme multipliers on PG splits.
+:Type: Integer
+:Default: 300
+
+
+``mon session timeout``
+
+:Description: Monitor will terminate inactive sessions stay idle over this
+ time limit.
+:Type: Integer
+:Default: 300
+
+
+
+.. _Paxos: http://en.wikipedia.org/wiki/Paxos_(computer_science)
+.. _Monitor Keyrings: ../../../dev/mon-bootstrap#secret-keys
+.. _Ceph configuration file: ../ceph-conf/#monitors
+.. _Network Configuration Reference: ../network-config-ref
+.. _Monitor lookup through DNS: ../mon-lookup-dns
+.. _ACID: http://en.wikipedia.org/wiki/ACID
+.. _Adding/Removing a Monitor: ../../operations/add-or-rm-mons
+.. _Add/Remove a Monitor (ceph-deploy): ../../deployment/ceph-deploy-mon
+.. _Monitoring a Cluster: ../../operations/monitoring
+.. _Monitoring OSDs and PGs: ../../operations/monitoring-osd-pg
+.. _Bootstrapping a Monitor: ../../../dev/mon-bootstrap
+.. _Changing a Monitor's IP Address: ../../operations/add-or-rm-mons#changing-a-monitor-s-ip-address
+.. _Monitor/OSD Interaction: ../mon-osd-interaction
+.. _Scalability and High Availability: ../../../architecture#scalability-and-high-availability
+.. _Pool values: ../../operations/pools/#set-pool-values
Code Review / stor4nfv.git / blobdiff