ceph/doc/mgr/localpool.rst
Sage Weil af72a8932c mgr/localpool: optionally adjust min_size too
Signed-off-by: Sage Weil <sage@redhat.com>
2017-10-02 17:13:12 -05:00

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Local pool plugin
=================
The *localpool* plugin can automatically create RADOS pools that are
localized to a subset of the overall cluster. For example, by default, it will
create a pool for each distinct rack in the cluster. This can be useful for some
deployments that want to distribute some data locally as well as globally across the cluster .
Enabling
--------
The *localpool* module is enabled with::
ceph mgr module enable localpool
Configuring
-----------
The *localpool* module understands the following options:
* **subtree** (default: `rack`): which CRUSH subtree type the module
should create a pool for.
* **failure_domain** (default: `host`): what failure domain we should
separate data replicas across.
* **pg_num** (default: `128`): number of PGs to create for each pool
* **num_rep** (default: `3`): number of replicas for each pool.
(Currently, pools are always replicated.)
* **min_size** (default: none): value to set min_size to (unchanged from Ceph's default if this option is not set)
* **prefix** (default: `by-$subtreetype-`): prefix for the pool name.
These options are set via the config-key interface. For example, to
change the replication level to 2x with only 64 PGs, ::
ceph config-key set mgr/localpool/num_rep 2
ceph config-key set mgr/localpool/pg_num 64