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diff --git a/doc/rados/configuration/pool-pg-config-ref.rst b/doc/rados/configuration/pool-pg-config-ref.rst new file mode 100644 index 000000000..b4b5df478 --- /dev/null +++ b/doc/rados/configuration/pool-pg-config-ref.rst @@ -0,0 +1,282 @@ +====================================== + Pool, PG and CRUSH Config Reference +====================================== + +.. index:: pools; configuration + +When you create pools and set the number of placement groups (PGs) for each, Ceph +uses default values when you don't specifically override the defaults. **We +recommend** overriding some of the defaults. Specifically, we recommend setting +a pool's replica size and overriding the default number of placement groups. You +can specifically set these values when running `pool`_ commands. You can also +override the defaults by adding new ones in the ``[global]`` section of your +Ceph configuration file. + + +.. literalinclude:: pool-pg.conf + :language: ini + + +``mon_max_pool_pg_num`` + +:Description: The maximum number of placement groups per pool. +:Type: Integer +:Default: ``65536`` + + +``mon_pg_create_interval`` + +:Description: Number of seconds between PG creation in the same + Ceph OSD Daemon. + +:Type: Float +:Default: ``30.0`` + + +``mon_pg_stuck_threshold`` + +:Description: Number of seconds after which PGs can be considered as + being stuck. + +:Type: 32-bit Integer +:Default: ``300`` + +``mon_pg_min_inactive`` + +:Description: Raise ``HEALTH_ERR`` if the count of PGs that have been + inactive longer than the ``mon_pg_stuck_threshold`` exceeds this + setting. A non-positive number means disabled, never go into ERR. +:Type: Integer +:Default: ``1`` + + +``mon_pg_warn_min_per_osd`` + +:Description: Raise ``HEALTH_WARN`` if the average number + of PGs per ``in`` OSD is under this number. A non-positive number + disables this. +:Type: Integer +:Default: ``30`` + + +``mon_pg_warn_min_objects`` + +:Description: Do not warn if the total number of RADOS objects in cluster is below + this number +:Type: Integer +:Default: ``1000`` + + +``mon_pg_warn_min_pool_objects`` + +:Description: Do not warn on pools whose RADOS object count is below this number +:Type: Integer +:Default: ``1000`` + + +``mon_pg_check_down_all_threshold`` + +:Description: Percentage threshold of ``down`` OSDs above which we check all PGs + for stale ones. +:Type: Float +:Default: ``0.5`` + + +``mon_pg_warn_max_object_skew`` + +:Description: Raise ``HEALTH_WARN`` if the average RADOS object count per PG + of any pool is greater than ``mon_pg_warn_max_object_skew`` times + the average RADOS object count per PG of all pools. Zero or a non-positive + number disables this. Note that this option applies to ``ceph-mgr`` daemons. +:Type: Float +:Default: ``10`` + + +``mon_delta_reset_interval`` + +:Description: Seconds of inactivity before we reset the PG delta to 0. We keep + track of the delta of the used space of each pool, so, for + example, it would be easier for us to understand the progress of + recovery or the performance of cache tier. But if there's no + activity reported for a certain pool, we just reset the history of + deltas of that pool. +:Type: Integer +:Default: ``10`` + + +``mon_osd_max_op_age`` + +:Description: Maximum op age before we get concerned (make it a power of 2). + ``HEALTH_WARN`` will be raised if a request has been blocked longer + than this limit. +:Type: Float +:Default: ``32.0`` + + +``osd_pg_bits`` + +:Description: Placement group bits per Ceph OSD Daemon. +:Type: 32-bit Integer +:Default: ``6`` + + +``osd_pgp_bits`` + +:Description: The number of bits per Ceph OSD Daemon for PGPs. +:Type: 32-bit Integer +:Default: ``6`` + + +``osd_crush_chooseleaf_type`` + +:Description: The bucket type to use for ``chooseleaf`` in a CRUSH rule. Uses + ordinal rank rather than name. + +:Type: 32-bit Integer +:Default: ``1``. Typically a host containing one or more Ceph OSD Daemons. + + +``osd_crush_initial_weight`` + +:Description: The initial CRUSH weight for newly added OSDs. + +:Type: Double +:Default: ``the size of a newly added OSD in TB``. By default, the initial CRUSH + weight for a newly added OSD is set to its device size in TB. + See `Weighting Bucket Items`_ for details. + + +``osd_pool_default_crush_rule`` + +:Description: The default CRUSH rule to use when creating a replicated pool. +:Type: 8-bit Integer +:Default: ``-1``, which means "pick the rule with the lowest numerical ID and + use that". This is to make pool creation work in the absence of rule 0. + + +``osd_pool_erasure_code_stripe_unit`` + +:Description: Sets the default size, in bytes, of a chunk of an object + stripe for erasure coded pools. Every object of size S + will be stored as N stripes, with each data chunk + receiving ``stripe unit`` bytes. Each stripe of ``N * + stripe unit`` bytes will be encoded/decoded + individually. This option can is overridden by the + ``stripe_unit`` setting in an erasure code profile. + +:Type: Unsigned 32-bit Integer +:Default: ``4096`` + + +``osd_pool_default_size`` + +:Description: Sets the number of replicas for objects in the pool. The default + value is the same as + ``ceph osd pool set {pool-name} size {size}``. + +:Type: 32-bit Integer +:Default: ``3`` + + +``osd_pool_default_min_size`` + +:Description: Sets the minimum number of written replicas for objects in the + pool in order to acknowledge a write operation to the client. If + minimum is not met, Ceph will not acknowledge the write to the + client, **which may result in data loss**. This setting ensures + a minimum number of replicas when operating in ``degraded`` mode. + +:Type: 32-bit Integer +:Default: ``0``, which means no particular minimum. If ``0``, + minimum is ``size - (size / 2)``. + + +``osd_pool_default_pg_num`` + +:Description: The default number of placement groups for a pool. The default + value is the same as ``pg_num`` with ``mkpool``. + +:Type: 32-bit Integer +:Default: ``32`` + + +``osd_pool_default_pgp_num`` + +:Description: The default number of placement groups for placement for a pool. + The default value is the same as ``pgp_num`` with ``mkpool``. + PG and PGP should be equal (for now). + +:Type: 32-bit Integer +:Default: ``8`` + + +``osd_pool_default_flags`` + +:Description: The default flags for new pools. +:Type: 32-bit Integer +:Default: ``0`` + + +``osd_max_pgls`` + +:Description: The maximum number of placement groups to list. A client + requesting a large number can tie up the Ceph OSD Daemon. + +:Type: Unsigned 64-bit Integer +:Default: ``1024`` +:Note: Default should be fine. + + +``osd_min_pg_log_entries`` + +:Description: The minimum number of placement group logs to maintain + when trimming log files. + +:Type: 32-bit Int Unsigned +:Default: ``250`` + + +``osd_max_pg_log_entries`` + +:Description: The maximum number of placement group logs to maintain + when trimming log files. + +:Type: 32-bit Int Unsigned +:Default: ``10000`` + + +``osd_default_data_pool_replay_window`` + +:Description: The time (in seconds) for an OSD to wait for a client to replay + a request. + +:Type: 32-bit Integer +:Default: ``45`` + +``osd_max_pg_per_osd_hard_ratio`` + +:Description: The ratio of number of PGs per OSD allowed by the cluster before the + OSD refuses to create new PGs. An OSD stops creating new PGs if the number + of PGs it serves exceeds + ``osd_max_pg_per_osd_hard_ratio`` \* ``mon_max_pg_per_osd``. + +:Type: Float +:Default: ``2`` + +``osd_recovery_priority`` + +:Description: Priority of recovery in the work queue. + +:Type: Integer +:Default: ``5`` + +``osd_recovery_op_priority`` + +:Description: Default priority used for recovery operations if pool doesn't override. + +:Type: Integer +:Default: ``3`` + +.. _pool: ../../operations/pools +.. _Monitoring OSDs and PGs: ../../operations/monitoring-osd-pg#peering +.. _Weighting Bucket Items: ../../operations/crush-map#weightingbucketitems |