doc/rados/operations/pools.rst: changes to scrub parameters

Following Tentacle changes to the operation of the cluster/pool
options that affect the determination of the 'max allowed time
to a scrub'.

Signed-off-by: Ronen Friedman <[email protected]>
(cherry picked from commit 6167345)

Author: ronen-fr

doc/rados/operations/pools.rst

@@ -551,7 +551,7 @@ You may set values for the following keys:
 
 .. describe:: scrub_min_interval
 
-   :Description: Sets the minimum interval (in seconds) between successive shallow / light scrubs of the pool's PGs when the load is low. If the default value of ``0`` is in effect, then the value of ``osd_scrub_min_interval`` from central config is used.
+   :Description: Sets the minimum interval (in seconds) between successive shallow (light) scrubs of the pool's PGs. If this pool attribute is unchanged from its default (``0``), the value of ``osd_scrub_min_interval`` from central config is used instead.
 
    :Type: Double
    :Default: ``0``
@@ -560,7 +560,7 @@ You may set values for the following keys:
 
 .. describe:: scrub_max_interval
 
-   :Description: Sets the maximum interval (in seconds) between successive shallow / light scrubs of the pool's PGs regardless of cluster load. If the value of ``scrub_max_interval`` is ``0``, then the value ``osd_scrub_max_interval`` from central config is used.
+   :Description: Sets the maximum interval (in seconds) between successive shallow (light) scrubs of the pool's PGs. Affects the 'overdue' attribute appearing in scrub scheduler dumps. If unchanged from its default of ``0``, the value of ``osd_scrub_max_interval`` from central config is used instead.
 
    :Type: Double
    :Default: ``0``
@@ -569,7 +569,7 @@ You may set values for the following keys:
 
 .. describe:: deep_scrub_interval
 
-   :Description: Sets the interval (in seconds) for successive pool deep scrubs of the pool's PGs. If the value of ``deep_scrub_interval`` is ``0``, the value ``osd_deep_scrub_interval`` from central config is used.
+   :Description: Sets the interval (in seconds) for successive pool deep scrubs of the pool's PGs. If unchanged from its default of ``0``, the value of ``osd_deep_scrub_interval`` from central config is used instead.
 
    :Type: Double
    :Default: ``0``