#. `Recompile`_ the CRUSH map.
#. `Set the CRUSH map`_.
-To activate CRUSH map rules for a specific pool, identify the common ruleset
-number for those rules and specify that ruleset number for the pool. See `Set
-Pool Values`_ for details.
+For details on setting the CRUSH map rule for a specific pool, see `Set
+Pool Values`_.
.. _Get the CRUSH map: #getcrushmap
.. _Decompile: #decompilecrushmap
---------------
CRUSH maps support the notion of 'CRUSH rules', which are the rules that
-determine data placement for a pool. For large clusters, you will likely create
-many pools where each pool may have its own CRUSH ruleset and rules. The default
-CRUSH map has a rule for each pool, and one ruleset assigned to each of the
-default pools.
+determine data placement for a pool. The default CRUSH map has a rule for each
+pool. For large clusters, you will likely create many pools where each pool may
+have its own non-default CRUSH rule.
-.. note:: In most cases, you will not need to modify the default rules. When
- you create a new pool, its default ruleset is ``0``.
+.. note:: In most cases, you will not need to modify the default rule. When
+ you create a new pool, by default the rule will be set to ``0``.
CRUSH rules define placement and replication strategies or distribution policies
``ruleset``
-:Description: A means of classifying a rule as belonging to a set of rules.
- Activated by `setting the ruleset in a pool`_.
+:Description: A unique whole number for identifying the rule. The name ``ruleset``
+ is a carry-over from the past, when it was possible to have multiple
+ CRUSH rules per pool.
:Purpose: A component of the rule mask.
:Type: Integer
:Required: Yes
:Default: 0
-.. _setting the ruleset in a pool: ../pools#setpoolvalues
-
``type``
:Prerequisite: Follows ``step choose``.
:Example: ``step emit``
-.. important:: To activate one or more rules with a common ruleset number to a
- pool, set the ruleset number of the pool.
+.. important:: A given CRUSH rule may be assigned to multiple pools, but it
+ is not possible for a single pool to have multiple CRUSH rules.
Placing Different Pools on Different OSDS: