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diff --git a/src/ceph/doc/rados/configuration/pool-pg-config-ref.rst b/src/ceph/doc/rados/configuration/pool-pg-config-ref.rst new file mode 100644 index 0000000..89a3707 --- /dev/null +++ b/src/ceph/doc/rados/configuration/pool-pg-config-ref.rst @@ -0,0 +1,270 @@ +====================================== + Pool, PG and CRUSH Config Reference +====================================== + +.. index:: pools; configuration + +When you create pools and set the number of placement groups for the pool, Ceph +uses default values when you don't specifically override the defaults. **We +recommend** overridding 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: Issue a ``HEALTH_ERR`` in cluster log if the number of PGs stay + inactive longer than ``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: Issue a ``HEALTH_WARN`` in cluster log 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 max per osd`` + +:Description: Issue a ``HEALTH_WARN`` in cluster log if the average number + of PGs per (in) OSD is above this number. (a non-positive number + disables this) +:Type: Integer +:Default: ``300`` + + +``mon pg warn min objects`` + +:Description: Do not warn if the total number of objects in cluster is below + this number +:Type: Integer +:Default: ``1000`` + + +``mon pg warn min pool objects`` + +:Description: Do not warn on pools whose object number is below this number +:Type: Integer +:Default: ``1000`` + + +``mon pg check down all threshold`` + +:Description: Threshold of down OSDs percentage after which we check all PGs + for stale ones. +:Type: Float +:Default: ``0.5`` + + +``mon pg warn max object skew`` + +:Description: Issue a ``HEALTH_WARN`` in cluster log if the average object number + of a certain pool is greater than ``mon pg warn max object skew`` times + the average object number of the whole pool. (a non-positive number + disables this) +: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). + A ``HEALTH_WARN`` will be issued 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 into crushmap. + +:Type: Double +:Default: ``the size of newly added osd in TB``. By default, the initial crush + weight for the newly added osd is set to its volume size in TB. + See `Weighting Bucket Items`_ for details. + + +``osd pool default crush replicated ruleset`` + +:Description: The default CRUSH ruleset to use when creating a replicated pool. +:Type: 8-bit Integer +:Default: ``CEPH_DEFAULT_CRUSH_REPLICATED_RULESET``, which means "pick + a ruleset with the lowest numerical ID and use that". This is to + make pool creation work in the absence of ruleset 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. 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: ``8`` + + +``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: ``1000`` + + +``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 + OSD refuses to create new PGs. 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`` + +.. _pool: ../../operations/pools +.. _Monitoring OSDs and PGs: ../../operations/monitoring-osd-pg#peering +.. _Weighting Bucket Items: ../../operations/crush-map#weightingbucketitems |