disabling the autoscaler for the duration of the upgrade. This is so that
PG splitting or merging in the middle of an upgrade does not unduly delay
upgrade progress. In a very large cluster this could easily increase the
- time to complete by a whole day or more, especially if the upgrade happens to
- change PG autoscaler behavior by e.g. changing the default value of
- the :confval:`mon_target_pg_per_osd`.
- |
- * ``ceph osd pool set noautoscale``
- * Perform the upgrade
- * ``ceph osd pool unset noautoscale``
- |
+ time to complete by a day or more, especially if the upgrade happens to
+ change PG autoscaler behavior by e.g. changing the default value
+ of :confval:`mon_target_pg_per_osd`.
+
+ .. prompt:: bash #
+
+ ceph osd pool set noautoscale
+ # Perform the upgrade
+ ceph osd pool unset noautoscale
+
When pausing autoscaler activity in this fashion, the existing values for
- each pool's mode, ``off``, ``on``, or ``warn`` are expected to remain.
+ each pool's mode, ``off``, ``on``, or ``warn``, are expected to remain.
If the new release changes the above target value, there may be splitting
or merging of PGs when unsetting after the upgrade.