Enabling
--------
-New clusters will have this module on by default. The cluster must only
-have luminous (and newer) clients. You can the turn the balancer off with::
+New clusters will by default enable the `balancer module`. The cluster must only
+have Luminous (and newer) clients. You can turn the balancer off with:
- ceph balancer off
+.. prompt:: bash $
+
+ ceph balancer off
To allow use of the feature on existing clusters, you must tell the
-cluster that it only needs to support luminous (and newer) clients with::
+cluster that it only needs to support Luminous (and newer) clients with:
+
+.. prompt:: bash $
- ceph osd set-require-min-compat-client luminous
+ ceph osd set-require-min-compat-client luminous
-This command will fail if any pre-luminous clients or daemons are
+This command will fail if any pre-Luminous clients or daemons are
connected to the monitors. You can see what client versions are in
-use with::
+use with:
+
+.. prompt:: bash $
- ceph features
+ ceph features
Balancer module
-----------------
Upmap entries are updated with an offline optimizer built into ``osdmaptool``.
-#. Grab the latest copy of your osdmap::
+#. Grab the latest copy of your osdmap:
- ceph osd getmap -o om
+ .. prompt:: bash $
-#. Run the optimizer::
+ ceph osd getmap -o om
- osdmaptool om --upmap out.txt [--upmap-pool <pool>]
- [--upmap-max <max-optimizations>] [--upmap-deviation <max-deviation>]
- [--upmap-active]
+#. Run the optimizer:
+
+ .. prompt:: bash $
+
+ osdmaptool om --upmap out.txt [--upmap-pool <pool>] \
+ [--upmap-max <max-optimizations>] \
+ [--upmap-deviation <max-deviation>] \
+ [--upmap-active]
It is highly recommended that optimization be done for each pool
individually, or for sets of similarly-utilized pools. You can
elapsed time for rounds indicates the CPU load ceph-mgr will be
consuming when it tries to compute the next optimization plan.
-#. Apply the changes::
+#. Apply the changes:
+
+ .. prompt:: bash $
- source out.txt
+ source out.txt
The proposed changes are written to the output file ``out.txt`` in
the example above. These are normal ceph CLI commands that can be