From: Zhiqiang Wang Date: Wed, 2 Sep 2015 06:00:40 +0000 (+0800) Subject: doc: add the doc for min_write_recency_for_promote X-Git-Tag: v9.1.0~203^2~3^2 X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=89aacaf699e7a126aa768b096331329e709a5108;p=ceph.git doc: add the doc for min_write_recency_for_promote Signed-off-by: Zhiqiang Wang --- diff --git a/doc/dev/cache-pool.rst b/doc/dev/cache-pool.rst index 2d22f1f3b7df0..7dc71c828e9ff 100644 --- a/doc/dev/cache-pool.rst +++ b/doc/dev/cache-pool.rst @@ -56,6 +56,7 @@ Set the target size and enable the tiering agent for foo-hot:: ceph osd pool set foo-hot hit_set_period 3600 # 1 hour ceph osd pool set foo-hot target_max_bytes 1000000000000 # 1 TB ceph osd pool set foo-hot min_read_recency_for_promote 1 + ceph osd pool set foo-hot min_write_recency_for_promote 1 Drain the cache in preparation for turning it off:: @@ -114,14 +115,18 @@ between 0 and ``hit_set_count``. If it's set to 0, the object is always promoted If it's set to 1, the current HitSet is checked. And if this object is in the current HitSet, it's promoted. Otherwise not. For the other values, the exact number of archive HitSets are checked. The object is promoted if the object is -found in any of the most recent ``min_read_recency_for_promote`` HitSets. :: +found in any of the most recent ``min_read_recency_for_promote`` HitSets. + +A similar parameter can be set for the write operation, which is +``min_write_recency_for_promote``. :: ceph osd pool set {cachepool} min_read_recency_for_promote 1 + ceph osd pool set {cachepool} min_write_recency_for_promote 1 Note that the longer the ``hit_set_period`` and the higher the -``min_read_recency_for_promote`` the more RAM will be consumed by the ceph-osd -process. In particular, when the agent is active to flush or evict cache objects, -all hit_set_count HitSets are loaded into RAM. +``min_read_recency_for_promote``/``min_write_recency_for_promote`` the more RAM +will be consumed by the ceph-osd process. In particular, when the agent is active +to flush or evict cache objects, all hit_set_count HitSets are loaded into RAM. Cache mode ~~~~~~~~~~ diff --git a/doc/rados/operations/cache-tiering.rst b/doc/rados/operations/cache-tiering.rst index f53526600d308..8275fe4381d39 100644 --- a/doc/rados/operations/cache-tiering.rst +++ b/doc/rados/operations/cache-tiering.rst @@ -193,14 +193,19 @@ between 0 and ``hit_set_count``. If it's set to 0, the object is always promoted If it's set to 1, the current HitSet is checked. And if this object is in the current HitSet, it's promoted. Otherwise not. For the other values, the exact number of archive HitSets are checked. The object is promoted if the object is -found in any of the most recent ``min_read_recency_for_promote`` HitSets. :: +found in any of the most recent ``min_read_recency_for_promote`` HitSets. + +A similar parameter can be set for the write operation, which is +``min_write_recency_for_promote``. :: ceph osd pool set {cachepool} min_read_recency_for_promote 1 + ceph osd pool set {cachepool} min_write_recency_for_promote 1 -.. note:: The longer the period and the higher the min_read_recency_for_promote, - the more RAM the ``ceph-osd`` daemon consumes. In particular, when the agent - is active to flush or evict cache objects, all ``hit_set_count`` HitSets are - loaded into RAM. +.. note:: The longer the period and the higher the + ``min_read_recency_for_promote``/``min_write_recency_for_promote``, the more + RAM the ``ceph-osd`` daemon consumes. In particular, when the agent is active + to flush or evict cache objects, all ``hit_set_count`` HitSets are loaded + into RAM. Cache Sizing