Output will be something like::
- POOL SIZE TARGET SIZE RATE RAW CAPACITY RATIO TARGET RATIO EFFECTIVE RATIO PG_NUM NEW PG_NUM AUTOSCALE
- a 12900M 3.0 82431M 0.4695 8 128 warn
- c 0 3.0 82431M 0.0000 0.2000 0.9884 1 64 warn
- b 0 953.6M 3.0 82431M 0.0347 8 warn
+ POOL SIZE TARGET SIZE RATE RAW CAPACITY RATIO TARGET RATIO EFFECTIVE RATIO BIAS PG_NUM NEW PG_NUM AUTOSCALE PROFILE
+ a 12900M 3.0 82431M 0.4695 8 128 warn scale-up
+ c 0 3.0 82431M 0.0000 0.2000 0.9884 1.0 1 64 warn scale-down
+ b 0 953.6M 3.0 82431M 0.0347 8 warn scale-down
**SIZE** is the amount of data stored in the pool. **TARGET SIZE**, if
present, is the amount of data the administrator has specified that
The system uses the larger of the actual ratio and the effective ratio
for its calculation.
+**BIAS** is used as a multiplier to manually adjust a pool's PG based
+on prior information about how much PGs a specific pool is expected
+to have.
+
**PG_NUM** is the current number of PGs for the pool (or the current
number of PGs that the pool is working towards, if a ``pg_num``
change is in progress). **NEW PG_NUM**, if present, is what the
always a power of 2, and will only be present if the "ideal" value
varies from the current value by more than a factor of 3.
-The final column, **AUTOSCALE**, is the pool ``pg_autoscale_mode``,
+**AUTOSCALE**, is the pool ``pg_autoscale_mode``
and will be either ``on``, ``off``, or ``warn``.
+The final column, **PROFILE** shows the autoscale profile
+used by each pool. ``scale-up`` and ``scale-down`` are the
+currently available profiles.
+
Automated scaling
-----------------
to OSDs of class `hdd` will each have optimal PG counts that depend on
the number of those respective device types.
+The autoscaler uses the `scale-down` profile by default,
+where each pool starts out with a full complements of PGs and only scales
+down when the usage ratio across the pools is not even. However, it also has
+a `scale-up` profile, where it starts out each pool with minimal PGs and scales
+up PGs when there is more usage in each pool.
+
+With only the `scale-down` profile, the autoscaler identifies
+any overlapping roots and prevents the pools with such roots
+from scaling because overlapping roots can cause problems
+with the scaling process.
+
+To use the `scale-up` profile::
+
+ ceph osd pool set autoscale-profile scale-up
+
+To switch back to the default `scale-down` profile::
+
+ ceph osd pool set autoscale-profile scale-down
+
+Existing clusters will continue to use the `scale-up` profile.
+To use the `scale-down` profile, users will need to set autoscale-profile `scale-down`,
+after upgrading to a version of Ceph that provides the `scale-down` feature.
.. _specifying_pool_target_size: