Appendix C. Ceph Monitor configuration options The following are Ceph monitor configuration options that can be set up during deployment. You can set these configuration options with the ceph config set mon CONFIGURATION_OPTION VALUE command. Configuration option Description Type Default mon_force_quorum_join Force monitor to join quorum even if it has been previously removed from the map Boolean False mon_dns_srv_name The service name used for querying the DNS for the monitor hosts/addresses. String ceph-mon fsid The cluster ID. One per cluster. UUID N/A. May be generated by a deployment tool if not specified. mon_data_size_warn Ceph issues a HEALTH_WARN status in the cluster log when the monitor's data store reaches this threshold. The default value is 15GB. Integer 15*1024*1024*1024* mon_data_avail_warn Ceph issues a HEALTH_WARN status in the cluster log when the available disk space of the monitor's data store is lower than or equal to this percentage. Integer 30 mon_data_avail_crit Ceph issues a HEALTH_ERR status in the cluster log when the available disk space of the monitor's data store is lower or equal to this percentage. Integer 5 mon_warn_on_cache_pools_without_hit_sets Ceph issues a HEALTH_WARN status in the cluster log if a cache pool does not have the hit_set_type parameter set. Boolean True mon_warn_on_crush_straw_calc_version_zero Ceph issues a HEALTH_WARN status in the cluster log if the CRUSH's straw_calc_version is zero. See CRUSH tunables for details. Boolean True mon_warn_on_legacy_crush_tunables Ceph issues a HEALTH_WARN status in the cluster log if CRUSH tunables are too old (older than mon_min_crush_required_version ). Boolean True mon_crush_min_required_version This setting defines the minimum tunable profile version required by the cluster. String hammer mon_warn_on_osd_down_out_interval_zero Ceph issues a HEALTH_WARN status in the cluster log if the mon_osd_down_out_interval setting is zero, because the Leader behaves in a similar manner when the noout flag is set. Administrators find it easier to troubleshoot a cluster by setting the noout flag. Ceph issues the warning to ensure administrators know that the setting is zero. Boolean True mon_health_to_clog This setting enables Ceph to send a health summary to the cluster log periodically. Boolean True mon_health_detail_to_clog This setting enable Ceph to send a health details to the cluster log periodically. Boolean True mon_op_complaint_time Number of seconds after which the Ceph Monitor operation is considered blocked after no updates. Integer 30 mon_health_to_clog_tick_interval How often (in seconds) the monitor sends a health summary to the cluster log. A non-positive number disables it. If the current health summary is empty or identical to the last time, the monitor will not send the status to the cluster log. Float 60.000000 mon_health_to_clog_interval How often (in seconds) the monitor sends a health summary to the cluster log. A non-positive number disables it. The monitor will always send the summary to the cluster log. Integer 600 mon_sync_timeout The number of seconds the monitor will wait for the update message from its sync provider before it gives up and bootstraps again. Double 60.000000 mon_sync_max_payload_size The maximum size for a sync payload (in bytes). 32-bit Integer 1045676 paxos_max_join_drift 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. Integer 10 paxos_stash_full_interval How often (in commits) to stash a full copy of the PaxosService state. Currently this setting only affects mds , mon , auth , and mgr PaxosServices. Integer 25 paxos_propose_interval Gather updates for this time interval before proposing a map update. Double 1.0 paxos_min The minimum number of paxos states to keep around Integer 500 paxos_min_wait The minimum amount of time to gather updates after a period of inactivity. Double 0.05 paxos_trim_min Number of extra proposals tolerated before trimming Integer 250 paxos_trim_max The maximum number of extra proposals to trim at a time Integer 500 paxos_service_trim_min The minimum amount of versions to trigger a trim (0 disables it) Integer 250 paxos_service_trim_max The maximum amount of versions to trim during a single proposal (0 disables it) Integer 500 mon_mds_force_trim_to Force monitor to trim mdsmaps to this point (0 disables it. Dangerous, use with care) Integer 0 mon_osd_force_trim_to 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) Integer 0 mon_osd_cache_size The size of osdmaps cache, not to rely on underlying store's cache Integer 500 mon_election_timeout On election proposer, maximum waiting time for all ACKs in seconds. Float 5 mon_lease The length (in seconds) of the lease on the monitor's versions. Float 5 mon_lease_renew_interval_factor 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 . Float 0.6 mon_lease_ack_timeout_factor The Leader will wait mon lease * mon lease ack timeout factor for the Providers to acknowledge the lease extension. Float 2.0 mon_min_osdmap_epochs Minimum number of OSD map epochs to keep at all times. 32-bit Integer 500 mon_max_log_epochs Maximum number of Log epochs the monitor should keep. 32-bit Integer 500 mon_tick_interval A monitor's tick interval in seconds. 32-bit Integer 5 mon_clock_drift_allowed The clock drift in seconds allowed between monitors. Float .050 mon_clock_drift_warn_backoff Exponential backoff for clock drift warnings. Float 5 mon_timecheck_interval The time check interval (clock drift check) in seconds for the leader. Float 300.0 mon_timecheck_skew_interval The time check interval (clock drift check) in seconds when in the presence of a skew in seconds for the Leader. Float 30.0 mon_max_osd The maximum number of OSDs allowed in the cluster. 32-bit Integer 10000 mon_globalid_prealloc The number of global IDs to pre-allocate for clients and daemons in the cluster. 32-bit Integer 10000 mon_subscribe_interval The refresh interval, in seconds, for subscriptions. The subscription mechanism enables obtaining the cluster maps and log information. Double 86400.000000 mon_stat_smooth_intervals Ceph will smooth statistics over the last N PG maps. Integer 6 mon_probe_timeout Number of seconds the monitor will wait to find peers before bootstrapping. Double 2.0 mon_daemon_bytes The message memory cap for metadata server and OSD messages (in bytes). 64-bit Integer Unsigned 400ul << 20 mon_max_log_entries_per_event The maximum number of log entries per event. Integer 4096 mon_osd_prime_pg_temp Enables or disable priming the PGMap with the OSDs when an out OSD comes back into the cluster. With the true setting, the clients will continue to use the OSDs until the newly in OSDs as that PG peered. Boolean true mon_osd_prime_pg_temp_max_time How much time in seconds the monitor should spend trying to prime the PGMap when an out OSD comes back into the cluster. Float 0.5 mon_lease_ack_timeout_factor The Leader will wait mon lease * mon lease ack timeout factor for the Providers to acknowledge the lease extension. Float 2.0 mon_accept_timeout_factor The Leader will wait mon lease * mon accept timeout factor for the Requesters to accept a Paxos update. It is also used during the Paxos recovery phase for similar purposes. Float 2.0 mon_min_osdmap_epochs Minimum number of OSD map epochs to keep at all times. 32-bit Integer 500 mon_max_pgmap_epochs Maximum number of PG map epochs the monitor should keep. 32-bit Integer 500 mon_max_log_epochs Maximum number of Log epochs the monitor should keep. 32-bit Integer 500 clock_offset How much to offset the system clock. See Clock.cc for details. Double 0 mon_tick_interval A monitor's tick interval in seconds. 32-bit Integer 5 mon_clock_drift_allowed The clock drift in seconds allowed between monitors. Float .050 mon_clock_drift_warn_backoff Exponential backoff for clock drift warnings. Float 5 mon_timecheck_interval The time check interval (clock drift check) in seconds for the leader. Float 300.0 mon_timecheck_skew_interval The time check interval (clock drift check) in seconds when in the presence of a skew in seconds for the Leader. Float 30.0 mon_max_osd The maximum number of OSDs allowed in the cluster. 32-bit Integer 10000 mon_globalid_prealloc The number of global IDs to pre-allocate for clients and daemons in the cluster. 32-bit Integer 10000 mon_sync_fs_threshold Synchronize with the filesystem when writing the specified number of objects. Set it to 0 to disable it. 32-bit Integer 5 mon_subscribe_interval The refresh interval, in seconds, for subscriptions. The subscription mechanism enables obtaining the cluster maps and log information. Double 86400.000000 mon_stat_smooth_intervals Ceph will smooth statistics over the last N PG maps. Integer 6 mon_probe_timeout Number of seconds the monitor will wait to find peers before bootstrapping. Double 2.0 mon_daemon_bytes The message memory cap for metadata server and OSD messages (in bytes). 64-bit Integer Unsigned 400ul << 20 mon_max_log_entries_per_event The maximum number of log entries per event. Integer 4096 mon_osd_prime_pg_temp Enables or disable priming the PGMap with the OSDs when an out OSD comes back into the cluster. With the true setting, the clients will continue to use the OSDs until the newly in OSDs as that PG peered. Boolean true mon_osd_prime_pg_temp_max_time How much time in seconds the monitor should spend trying to prime the PGMap when an out OSD comes back into the cluster. Float 0.5 mon_mds_skip_sanity 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. Boolean False mon_max_mdsmap_epochs The maximum amount of mdsmap epochs to trim during a single proposal. Integer 500 mon_config_key_max_entry_size The maximum size of config-key entry (in bytes). Integer 65536 mon_warn_pg_not_scrubbed_ratio The percentage of the scrub max interval past the scrub max interval to warn. float 0.5 mon_warn_pg_not_deep_scrubbed_ratio The percentage of the deep scrub interval past the deep scrub interval to warn float 0.75 mon_scrub_interval How often, in seconds, the monitor scrub its store by comparing the stored checksums with the computed ones of all the stored keys. Integer 3600*24 mon_scrub_timeout The timeout to restart scrub of mon quorum participant does not respond for the latest chunk. Integer 5 min mon_scrub_max_keys The maximum number of keys to scrub each time. Integer 100 mon_scrub_inject_missing_keys The probability of injecting missing keys into mon scrub. Float 0 mon_compact_on_start Compact the database used as Ceph Monitor store on ceph-mon start. A manual compaction helps to shrink the monitor database and improve its performance if the regular compaction fails to work. Boolean False mon_compact_on_bootstrap Compact the database used as Ceph Monitor store on bootstrap. The 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. Boolean False mon_compact_on_trim Compact a certain prefix (including paxos) when we trim its old states. Boolean True mon_osd_mapping_pgs_per_chunk We calculate the mapping from the placement group to OSDs in chunks. This option specifies the number of placement groups per chunk. Integer 4096 rados_mon_op_timeout Number of seconds to wait for a response from the monitor before returning an error from a rados operation. 0 means at limit, or no wait time. Double 0 Additional Resources Pool Values CRUSH tunables

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