From: Melissa Li Date: Thu, 23 Dec 2021 22:16:07 +0000 (-0500) Subject: doc/cephadm: warn about default enabling `osd_memory_target_autotune` X-Git-Tag: v17.1.0~66^2~1 X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=0fad0fde9cfddf92113817fd8311a24888523efb;p=ceph.git doc/cephadm: warn about default enabling `osd_memory_target_autotune` Fixes: https://tracker.ceph.com/issues/51562 Signed-off-by: Melissa Li --- diff --git a/doc/cephadm/install.rst b/doc/cephadm/install.rst index 95d65380afa..1109f360a09 100644 --- a/doc/cephadm/install.rst +++ b/doc/cephadm/install.rst @@ -362,11 +362,14 @@ See :ref:`cephadm-deploy-osds` for more detailed instructions. Enabling OSD memory autotuning ------------------------------ -It is recommended to enable ``osd_memory_target_autotune``. -in order to maximise the performance of the cluster. See :ref:`osd_autotune`. +.. warning:: By default, cephadm enables ``osd_memory_target_autotune`` on bootstrap, with ``mgr/cephadm/autotune_memory_target_ratio`` set to ``.7`` of total host memory. -In case the cluster hardware is not exclusively used by Ceph (hyperconverged), -reduce the memory consuption of Ceph like so: +See :ref:`osd_autotune`. + +To deploy hyperconverged Ceph with TripleO, please refer to the TripleO documentation: `Scenario: Deploy Hyperconverged Ceph `_ + +In other cases where the cluster hardware is not exclusively used by Ceph (hyperconverged), +reduce the memory consumption of Ceph like so: .. prompt:: bash # diff --git a/doc/cephadm/services/osd.rst b/doc/cephadm/services/osd.rst index 32f50e2d47f..c96d8a51086 100644 --- a/doc/cephadm/services/osd.rst +++ b/doc/cephadm/services/osd.rst @@ -380,9 +380,7 @@ memory with other services, cephadm can automatically adjust the per-OSD memory consumption based on the total amount of RAM and the number of deployed OSDs. -This option is enabled globally with:: - - ceph config set osd osd_memory_target_autotune true +.. warning:: Cephadm sets ``osd_memory_target_autotune`` to ``true`` by default which is unsuitable for hyperconverged infrastructures. Cephadm will start with a fraction (``mgr/cephadm/autotune_memory_target_ratio``, which defaults to