Object Storage Daemon (OSD) configuration options
Understand the various Ceph Object Storage Daemon (OSD) configuration options that can be set during deployment.
You can set these configuration options with the ceph config set osd CONFIGURATION_OPTION VALUE command.
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osd_uuid -
Description: The universally unique identifier (UUID) for the Ceph OSD.
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osd_data -
Description: The path to the OSD’s data. You must create the directory when deploying Ceph. Mount a drive for OSD data at this mount point.
-
osd_max_write_size -
Description: The maximum size of a write in megabytes.
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osd_client_message_size_cap -
Description: The largest client data message allowed in memory.
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osd_class_dir -
Description: The class path for RADOS class plug-ins.
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osd_max_scrubs -
Description: The maximum number of simultaneous scrub operations for a Ceph OSD.
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osd_scrub_thread_timeout -
Description: The maximum time in seconds before timing out a scrub thread.
-
osd_scrub_finalize_thread_timeout -
Description: The maximum time in seconds before timing out a scrub finalize thread.
-
osd_scrub_begin_hour -
Description: This restricts scrubbing to this hour of the day or later. Use
osd_scrub_begin_hour = 0andosd_scrub_end_hour = 0to allow scrubbing the entire day. Along withosd_scrub_end_hour, they define a time window, in which the scrubs can happen. But a scrub is performed no matter whether the time window allows or not, as long as the placement group’s scrub interval exceedsosd_scrub_max_interval. -
osd_scrub_end_hour -
Description: This restricts scrubbing to the hour earlier than this. Use
osd_scrub_begin_hour=0andosd_scrub_end_hour=0to allow scrubbing for the entire day. Along withosd_scrub_begin_hour, they define a time window, in which the scrubs can happen. But a scrub is performed no matter whether the time window allows or not, as long as the placement group's scrub interval exceedsosd_scrub_max_interval. -
osd_scrub_load_threshold -
Description: The maximum load. Ceph will not scrub when the system load (as defined by the
getloadavg()function) is higher than this number. Default is0.5. -
osd_scrub_min_interval -
Description: The minimum interval in seconds for scrubbing the Ceph OSD when the IBM Storage Ceph cluster load is low.
-
osd_scrub_max_interval -
Description: The maximum interval in seconds for scrubbing the Ceph OSD irrespective of cluster load.
-
osd_scrub_interval_randomize_ratio -
Description: Takes the ratio and randomizes the scheduled scrub between
osd scrub min intervalandosd scrub max interval. -
mon_warn_not_scrubbed -
Description: Number of seconds after
osd_scrub_intervalto warn about any PGs that were not scrubbed. -
osd_scrub_chunk_min -
Description: The object store is partitioned into chunks which end on hash boundaries. For chunky scrubs, Ceph scrubs objects one chunk at a time with writes blocked for that chunk. The
osd scrubchunk minsetting represents the minimum number of chunks to scrub. -
osd_scrub_chunk_max -
Description: The maximum number of chunks to scrub.
-
osd_scrub_sleep -
Description: The time to sleep between deep scrub operations.
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osd_scrub_during_recovery -
Description: Allows scrubbing during recovery.
-
osd_scrub_invalid_stats -
Description: Forces extra scrub to fix stats marked as invalid.
-
osd_scrub_priority -
Description: Controls queue priority of scrub operations versus client I/O.
-
osd_requested_scrub_priority -
Description: The priority set for user requested scrub on the work queue. If this value were to be smaller than
osd_client_op_priority, it can be boosted to the value ofosd_client_op_prioritywhen scrub is blocking client operations. -
osd_scrub_cost -
Description: Cost of scrub operations in megabytes for queue scheduling purposes.
-
osd_deep_scrub_interval -
Description: The interval for deep scrubbing, that is fully reading all data. The
osd scrub load thresholdparameter does not affect this setting. -
osd_deep_scrub_stride -
Description: Read size when doing a deep scrub.
-
mon_warn_not_deep_scrubbed -
Description: Number of seconds after
osd_deep_scrub_intervalto warn about any PGs that were not scrubbed. -
osd_deep_scrub_randomize_ratio -
Description: The rate at which scrubs will randomly become deep scrubs (even before
osd_deep_scrub_intervalhas passed). -
osd_deep_scrub_update_digest_min_age -
Description: How many seconds old objects must be before scrub updates the whole-object digest.
-
osd_deep_scrub_large_omap_object_key_threshold -
Description: Warning when you encounter an object with more OMAP keys than this.
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osd_deep_scrub_large_omap_object_value_sum_threshold -
Description: Warning when you encounter an object with more OMAP key bytes than this.
-
osd_delete_sleep -
Description: Time in seconds to sleep before the next removal transaction. This throttles the placement group deletion process.
-
osd_delete_sleep_hdd -
Description: Time in seconds to sleep before the next removal transaction for HDDs.
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osd_delete_sleep_ssd -
Description: Time in seconds to sleep before the next removal transaction for SSDs.
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osd_delete_sleep_hybrid -
Description: Time in seconds to sleep before the next removal transaction when Ceph OSD data is on HDD and OSD journal or WAL and DB is on SSD.
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osd_op_num_shards -
Description: The number of shards for client operations.
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osd_op_num_threads_per_shard -
Description: The number of threads per shard for client operations.
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osd_op_num_shards_hdd -
Description: The number of shards for HDD operations.
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osd_op_num_threads_per_shard_hdd -
Description: The number of threads per shard for HDD operations.
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osd_op_num_shards_ssd -
Description: The number of shards for SSD operations.
-
osd_op_num_threads_per_shard_ssd -
Description: The number of threads per shard for SSD operations.
-
osd_client_op_priority -
Description: The priority set for client operations. It is relative to
osd recovery op priority. -
osd_recovery_op_priority -
Description: The priority set for recovery operations. It is relative to
osd client op priority. -
osd_op_thread_timeout -
Description: The Ceph OSD operation thread timeout in seconds.
-
osd_op_complaint_time -
Description: An operation becomes complaint worthy after the specified number of seconds have elapsed.
-
osd_disk_threads -
Description: The number of disk threads, which are used to perform background disk intensive OSD operations such as scrubbing and snap trimming.
-
osd_op_history_size -
Description: The maximum number of completed operations to track.
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osd_op_history_duration -
Description: The oldest completed operation to track.
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osd_op_log_threshold -
Description: How many operations logs to display at once.
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osd_op_timeout -
Description: The time in seconds after which running OSD operations time out.
-
osd_max_backfills -
Description: The maximum number of backfill operations allowed to or from a single OSD.
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osd_backfill_scan_min -
Description: The minimum number of objects per backfill scan.
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osd_backfill_scan_max -
Description: The maximum number of objects per backfill scan.
-
osd_backfill_full_ratio -
Description: Refuse to accept backfill requests when the Ceph OSD’s full ratio is above this value.
-
osd_backfill_retry_interval -
Description: The number of seconds to wait before retrying backfill requests.
-
osd_map_dedup -
Description: Enable removing duplicates in the OSD map.
-
osd_map_cache_size -
Description: The size of the OSD map cache in megabytes.
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osd_map_cache_bl_size -
Description: The size of the in-memory OSD map cache in OSD daemons.
-
osd_map_cache_bl_inc_size -
Description: The size of the in-memory OSD map cache incrementals in OSD daemons.
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osd_map_message_max -
Description: The maximum map entries allowed per MOSDMap message.
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osd_snap_trim_thread_timeout -
Description: The maximum time in seconds before timing out a snap trim thread.
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osd_pg_max_concurrent_snap_trims -
Description: The max number of parallel snap trims/PG. This controls how many objects per PG to trim at once.
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osd_snap_trim_sleep -
Description: Insert a sleep between every trim operation a PG issues.
-
osd_max_trimming_pgs -
Description: The max number of trimming PGs
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osd_backlog_thread_timeout -
Description: The maximum time in seconds before timing out a backlog thread.
-
osd_default_notify_timeout -
Description: The OSD default notification timeout (in seconds).
-
osd_check_for_log_corruption -
Description: Check log files for corruption. Can be computationally expensive.
-
osd_remove_thread_timeout -
Description: The maximum time in seconds before timing out a remove OSD thread.
-
osd_command_thread_timeout -
Description: The maximum time in seconds before timing out a command thread.
-
osd_command_max_records -
Description: Limits the number of lost objects to return.
-
osd_auto_upgrade_tmap -
Description: Uses
tmapforomapon old objects. -
osd_tmapput_sets_users_tmap -
Description: Uses
tmapfor debugging only. -
osd_preserve_trimmed_log -
Description: Preserves trimmed log files, but uses more disk space.
-
osd_recovery_delay_start -
Description: After peering completes, Ceph delays for the specified number of seconds before starting to recover objects.
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osd_recovery_max_active -
Description: The number of active recovery requests per OSD at one time. More requests will accelerate recovery, but the requests place an increased load on the cluster.
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osd_recovery_max_chunk -
Description: The maximum size of a recovered chunk of data to push.
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osd_recovery_threads -
Description: The number of threads for recovering data.
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osd_recovery_thread_timeout -
Description: The maximum time in seconds before timing out a recovery thread.
-
osd_recover_clone_overlap -
Description: Preserves clone overlap during recovery. Should always be set to
true. -
rados_osd_op_timeout -
Description: Number of seconds that RADOS waits for a response from the OSD before returning an error from a RADOS operation. A value of 0 means no limit.