the ``ceph-mgr`` *balancer* module to perform these tasks automatically if the
cluster is running Luminous or a later release.
-
Modifying the CRUSH map
=======================
.. _addosd:
-Add/Move an OSD
----------------
+Adding/Moving an OSD
+--------------------
-.. note: OSDs are normally automatically added to the CRUSH map when
- the OSD is created. This command is rarely needed.
+.. note:: Under normal conditions, OSDs automatically add themselves to the
+ CRUSH map when they are created. The command in this section is rarely
+ needed.
-To add or move an OSD in the CRUSH map of a running cluster:
+
+To add or move an OSD in the CRUSH map of a running cluster, run a command of
+the following form:
.. prompt:: bash $
ceph osd crush set {name} {weight} root={root} [{bucket-type}={bucket-name} ...]
-Where:
+For details on this command's parameters, see the following:
``name``
-
-:Description: The full name of the OSD.
-:Type: String
-:Required: Yes
-:Example: ``osd.0``
+ :Description: The full name of the OSD.
+ :Type: String
+ :Required: Yes
+ :Example: ``osd.0``
``weight``
-
-:Description: The CRUSH weight for the OSD, normally its size measure in terabytes (TB).
-:Type: Double
-:Required: Yes
-:Example: ``2.0``
+ :Description: The CRUSH weight of the OSD. Normally, this is its size, as measured in terabytes (TB).
+ :Type: Double
+ :Required: Yes
+ :Example: ``2.0``
``root``
-
-:Description: The root node of the tree in which the OSD resides (normally ``default``)
-:Type: Key/value pair.
-:Required: Yes
-:Example: ``root=default``
+ :Description: The root node of the CRUSH hierarchy in which the OSD resides (normally ``default``).
+ :Type: Key-value pair.
+ :Required: Yes
+ :Example: ``root=default``
``bucket-type``
+ :Description: The OSD's location in the CRUSH hierarchy.
+ :Type: Key-value pairs.
+ :Required: No
+ :Example: ``datacenter=dc1 room=room1 row=foo rack=bar host=foo-bar-1``
-:Description: You may specify the OSD's location in the CRUSH hierarchy.
-:Type: Key/value pairs.
-:Required: No
-:Example: ``datacenter=dc1 room=room1 row=foo rack=bar host=foo-bar-1``
-
-
-The following example adds ``osd.0`` to the hierarchy, or moves the
-OSD from a previous location:
+In the following example, the command adds ``osd.0`` to the hierarchy, or moves
+``osd.0`` from a previous location:
.. prompt:: bash $
ceph osd crush set osd.0 1.0 root=default datacenter=dc1 room=room1 row=foo rack=bar host=foo-bar-1
-Adjust OSD weight
------------------
+Adjusting OSD weight
+--------------------
-.. note: Normally OSDs automatically add themselves to the CRUSH map
- with the correct weight when they are created. This command
- is rarely needed.
+.. note:: Under normal conditions, OSDs automatically add themselves to the
+ CRUSH map with the correct weight when they are created. The command in this
+ section is rarely needed.
-To adjust an OSD's CRUSH weight in the CRUSH map of a running cluster, execute
-the following:
+To adjust an OSD's CRUSH weight in a running cluster, run a command of the
+following form:
.. prompt:: bash $
ceph osd crush reweight {name} {weight}
-Where:
+For details on this command's parameters, see the following:
``name``
-
-:Description: The full name of the OSD.
-:Type: String
-:Required: Yes
-:Example: ``osd.0``
+ :Description: The full name of the OSD.
+ :Type: String
+ :Required: Yes
+ :Example: ``osd.0``
``weight``
-
-:Description: The CRUSH weight for the OSD.
-:Type: Double
-:Required: Yes
-:Example: ``2.0``
+ :Description: The CRUSH weight of the OSD.
+ :Type: Double
+ :Required: Yes
+ :Example: ``2.0``
.. _removeosd:
-Remove an OSD
--------------
+Removing an OSD
+---------------
-.. note: OSDs are normally removed from the CRUSH as part of the
- ``ceph osd purge`` command. This command is rarely needed.
+.. note:: OSDs are normally removed from the CRUSH map as a result of the
+ `ceph osd purge`` command. This command is rarely needed.
-To remove an OSD from the CRUSH map of a running cluster, execute the
-following:
+To remove an OSD from the CRUSH map of a running cluster, run a command of the
+following form:
.. prompt:: bash $
ceph osd crush remove {name}
-Where:
+For details on the ``name`` parameter, see the following:
``name``
-
-:Description: The full name of the OSD.
-:Type: String
-:Required: Yes
-:Example: ``osd.0``
+ :Description: The full name of the OSD.
+ :Type: String
+ :Required: Yes
+ :Example: ``osd.0``
-Add a Bucket
-------------
-
-.. note: Buckets are implicitly created when an OSD is added
- that specifies a ``{bucket-type}={bucket-name}`` as part of its
- location, if a bucket with that name does not already exist. This
- command is typically used when manually adjusting the structure of the
- hierarchy after OSDs have been created. One use is to move a
- series of hosts underneath a new rack-level bucket; another is to
- add new ``host`` buckets (OSD nodes) to a dummy ``root`` so that they don't
- receive data until you're ready, at which time you would move them to the
- ``default`` or other root as described below.
+Adding a CRUSH Bucket
+---------------------
-To add a bucket in the CRUSH map of a running cluster, execute the
-``ceph osd crush add-bucket`` command:
+.. note:: Buckets are implicitly created when an OSD is added and the command
+ that creates it specifies a ``{bucket-type}={bucket-name}`` as part of the
+ OSD's location (provided that a bucket with that name does not already
+ exist). The command in this section is typically used when manually
+ adjusting the structure of the hierarchy after OSDs have already been
+ created. One use of this command is to move a series of hosts to a new
+ rack-level bucket. Another use of this command is to add new ``host``
+ buckets (OSD nodes) to a dummy ``root`` so that the buckets don't receive
+ any data until they are ready to receive data. When they are ready, move the
+ buckets to the ``default`` root or to any other root as described below.
+
+To add a bucket in the CRUSH map of a running cluster, run a command of the
+following form:
.. prompt:: bash $
ceph osd crush add-bucket {bucket-name} {bucket-type}
-Where:
+For details on this command's parameters, see the following:
``bucket-name``
-
-:Description: The full name of the bucket.
-:Type: String
-:Required: Yes
-:Example: ``rack12``
+ :Description: The full name of the bucket.
+ :Type: String
+ :Required: Yes
+ :Example: ``rack12``
``bucket-type``
+ :Description: The type of the bucket. This type must already exist in the CRUSH hierarchy.
+ :Type: String
+ :Required: Yes
+ :Example: ``rack``
-:Description: The type of the bucket. The type must already exist in the hierarchy.
-:Type: String
-:Required: Yes
-:Example: ``rack``
-
-
-The following example adds the ``rack12`` bucket to the hierarchy:
+In the following example, the command adds the ``rack12`` bucket to the hierarchy:
.. prompt:: bash $
ceph osd crush add-bucket rack12 rack
-Move a Bucket
--------------
+Moving a Bucket
+---------------
To move a bucket to a different location or position in the CRUSH map
-hierarchy, execute the following:
+hierarchy, run a command of the following form:
.. prompt:: bash $
ceph osd crush move {bucket-name} {bucket-type}={bucket-name}, [...]
-Where:
+For details on this command's parameters, see the following:
``bucket-name``
-
-:Description: The name of the bucket to move/reposition.
-:Type: String
-:Required: Yes
-:Example: ``foo-bar-1``
+ :Description: The name of the bucket that you are moving.
+ :Type: String
+ :Required: Yes
+ :Example: ``foo-bar-1``
``bucket-type``
+ :Description: The bucket's new location in the CRUSH hierarchy.
+ :Type: Key-value pairs.
+ :Required: No
+ :Example: ``datacenter=dc1 room=room1 row=foo rack=bar host=foo-bar-1``
-:Description: You may specify the bucket's location in the CRUSH hierarchy.
-:Type: Key/value pairs.
-:Required: No
-:Example: ``datacenter=dc1 room=room1 row=foo rack=bar host=foo-bar-1``
-
-Remove a Bucket
----------------
+Removing a Bucket
+-----------------
-To remove a bucket from the CRUSH hierarchy, execute the following:
+To remove a bucket from the CRUSH hierarchy, run a command of the following
+form:
.. prompt:: bash $
ceph osd crush remove {bucket-name}
-.. note:: A bucket must be empty before removing it from the CRUSH hierarchy.
+.. note:: A bucket must already be empty before it is removed from the CRUSH
+ hierarchy. In other words, there must not be OSDs or any other CRUSH buckets
+ within it.
-Where:
+For details on the ``bucket-name`` parameter, see the following:
``bucket-name``
+ :Description: The name of the bucket that is being removed.
+ :Type: String
+ :Required: Yes
+ :Example: ``rack12``
-:Description: The name of the bucket that you'd like to remove.
-:Type: String
-:Required: Yes
-:Example: ``rack12``
-
-The following example removes the ``rack12`` bucket from the hierarchy:
+In the following example, the command removes the ``rack12`` bucket from the
+hierarchy:
.. prompt:: bash $
Creating a compat weight set
----------------------------
-.. note: This step is normally done automatically by the ``balancer``
- module when enabled.
+.. note:: Normally this action is done automatically if needed by the
+ ``balancer`` module (provided that the module is enabled).
-To create a *compat* weight set:
+To create a *compat* weight set, run the following command:
.. prompt:: bash $
ceph osd crush weight-set create-compat
-Weights for the compat weight set can be adjusted with:
+To adjust the weights of the compat weight set, run a command of the following
+form:
.. prompt:: bash $
ceph osd crush weight-set reweight-compat {name} {weight}
-The compat weight set can be destroyed with:
+To destroy the compat weight set, run the following command:
.. prompt:: bash $
Creating per-pool weight sets
-----------------------------
-To create a weight set for a specific pool:
+To create a weight set for a specific pool, run a command of the following
+form:
.. prompt:: bash $
ceph osd crush weight-set create {pool-name} {mode}
-.. note:: Per-pool weight sets require that all servers and daemons
- run Luminous v12.2.z or later.
+.. note:: Per-pool weight sets can be used only if all servers and daemons are
+ running Luminous v12.2.z or a later release.
-Where:
+For details on this command's parameters, see the following:
``pool-name``
-
-:Description: The name of a RADOS pool
-:Type: String
-:Required: Yes
-:Example: ``rbd``
+ :Description: The name of a RADOS pool.
+ :Type: String
+ :Required: Yes
+ :Example: ``rbd``
``mode``
-
-:Description: Either ``flat`` or ``positional``. A *flat* weight set
- has a single weight for each device or bucket. A
- *positional* weight set has a potentially different
- weight for each position in the resulting placement
- mapping. For example, if a pool has a replica count of
- 3, then a positional weight set will have three weights
- for each device and bucket.
-:Type: String
-:Required: Yes
-:Example: ``flat``
-
-To adjust the weight of an item in a weight set:
+ :Description: Either ``flat`` or ``positional``. A *flat* weight set
+ assigns a single weight to all devices or buckets. A
+ *positional* weight set has a potentially different
+ weight for each position in the resulting placement
+ mapping. For example: if a pool has a replica count of
+ ``3``, then a positional weight set will have three
+ weights for each device and bucket.
+ :Type: String
+ :Required: Yes
+ :Example: ``flat``
+
+To adjust the weight of an item in a weight set, run a command of the following
+form:
.. prompt:: bash $
ceph osd crush weight-set reweight {pool-name} {item-name} {weight [...]}
-To list existing weight sets:
+To list existing weight sets, run the following command:
.. prompt:: bash $
ceph osd crush weight-set ls
-To remove a weight set:
+To remove a weight set, run a command of the following form:
.. prompt:: bash $
ceph osd crush weight-set rm {pool-name}
+
Creating a rule for a replicated pool
-------------------------------------
projects / ceph.git / commitdiff