From: Anthony D'Atri Date: Sat, 17 Jun 2023 10:37:58 +0000 (-0400) Subject: doc/rados/operations: Improve formatting in crush-map.rst X-Git-Tag: v19.0.0~994^2 X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=540d6ce3ee014a6ad1560e628c8d04e694a0c599;p=ceph-ci.git doc/rados/operations: Improve formatting in crush-map.rst Signed-off-by: Anthony D'Atri --- diff --git a/doc/rados/operations/crush-map.rst b/doc/rados/operations/crush-map.rst index 5c37eea88aa..ac4f1cb12a1 100644 --- a/doc/rados/operations/crush-map.rst +++ b/doc/rados/operations/crush-map.rst @@ -763,7 +763,7 @@ most clusters, provided that not many OSDs have been marked ``out``. bobtail (CRUSH_TUNABLES2) ------------------------- -The ``bobtail`` tunable profile provides the following fixes: +The ``bobtail`` tunable profile provides the following improvements: * For hierarchies with a small number of devices in leaf buckets, some PGs might map to fewer than the desired number of replicas, resulting in @@ -779,7 +779,7 @@ The ``bobtail`` tunable profile provides the following fixes: * When one or more OSDs are marked ``out``, data tends to be redistributed to nearby OSDs instead of across the entire hierarchy. -The tunables introduced by ``bobtail`` are as follows: +The tunables introduced in the Bobtail release are as follows: * ``choose_local_tries``: Number of local retries. The legacy value is ``2``, and the optimal value is ``0``. @@ -808,10 +808,10 @@ firefly (CRUSH_TUNABLES3) chooseleaf_vary_r ~~~~~~~~~~~~~~~~~ -This ``firefly`` tunable profile fixes a problem with ``chooseleaf`` CRUSH rule -behavior. This problem arose when too many OSDs were marked ``out``, which resulted in PG mappings with too few OSDs. +This ``firefly`` tunable profile fixes a problem with ``chooseleaf`` CRUSH step +behavior. This problem arose when a large fraction of OSDs were marked ``out``, which resulted in PG mappings with too few OSDs. -This tunable, introduced in ``firefly``, is as follows: +This profile was introduced in the Firefly release, and adds a new tunable as follows: * ``chooseleaf_vary_r``: Whether a recursive chooseleaf attempt will start with a non-zero value of ``r``, as determined by the number of attempts the @@ -830,11 +830,11 @@ straw_calc_version tunable ~~~~~~~~~~~~~~~~~~~~~~~~~~ There were problems with the internal weights calculated and stored in the -CRUSH map for ``straw`` algorithm buckets. When there were items with a CRUSH +CRUSH map for ``straw`` algorithm buckets. When there were buckets with a CRUSH weight of ``0`` or with a mix of different and unique weights, CRUSH would distribute data incorrectly (that is, not in proportion to the weights). -This tunable, introduced in ``Firefly``, is as follows: +This tunable, introduced in the Firefly release, is as follows: * ``straw_calc_version``: A value of ``0`` preserves the old, broken internal-weight calculation; a value of ``1`` fixes the problem. @@ -847,7 +847,7 @@ Migration impact: movement provided that the cluster has hit one of the problematic conditions. -This tunable option is special because it has absolutely no impact on the +This tunable option is notable in that it has absolutely no impact on the required kernel version in the client side. hammer (CRUSH_V4) @@ -880,7 +880,7 @@ The ``jewel`` tunable profile improves the overall behavior of CRUSH. As a result, significantly fewer mappings change when an OSD is marked ``out`` of the cluster. This improvement results in significantly less data movement. -The new tunable introduced by ``jewel`` is as follows: +The new tunable introduced in the Jewel release is as follows: * ``chooseleaf_stable``: Determines whether a recursive chooseleaf attempt will use a better value for an inner loop that greatly reduces the number of