From: Neha Date: Thu, 12 Dec 2019 22:04:57 +0000 (+0000) Subject: doc/rados: Better block.db size recommendations for bluestore X-Git-Tag: v15.1.0~509^2 X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=36cdafbcca5a42199cb16937ee6c9f912dab1de8;p=ceph-ci.git doc/rados: Better block.db size recommendations for bluestore Signed-off-by: Neha Ojha --- diff --git a/doc/rados/configuration/bluestore-config-ref.rst b/doc/rados/configuration/bluestore-config-ref.rst index d728775d46a..bcc8476ab8d 100644 --- a/doc/rados/configuration/bluestore-config-ref.rst +++ b/doc/rados/configuration/bluestore-config-ref.rst @@ -127,9 +127,11 @@ When using a :ref:`mixed spinning and solid drive setup ``block.db`` logical volume for Bluestore. Generally, ``block.db`` should have *as large as possible* logical volumes. -It is recommended that the ``block.db`` size isn't smaller than 4% of -``block``. For example, if the ``block`` size is 1TB, then ``block.db`` -shouldn't be less than 40GB. +The general recommendation is to have ``block.db`` size in between 1% to 4% +of ``block`` size. For RGW workloads, it is recommended that the ``block.db`` +size isn't smaller than 4% of ``block``, because RGW heavily uses it to store its +metadata. For example, if the ``block`` size is 1TB, then ``block.db`` shouldn't +be less than 40GB. For RBD workloads, 1% to 2% of ``block`` size is usually enough. If *not* using a mix of fast and slow devices, it isn't required to create separate logical volumes for ``block.db`` (or ``block.wal``). Bluestore will