doc/rados: link to pg setting commands

Link to the instructions for manually setting the number of PGs per
pool, from the mention of placement groups. These instructions are
included here in response to a request from Ronen Friedman on the
occasion of the removal of links to the PGcalc (see
https://github.com/ceph/ceph/pull/55899#pullrequestreview-1912940118).

Signed-off-by: Zac Dover <zac.dover@proton.me>

diff --git a/doc/rados/operations/pools.rst b/doc/rados/operations/pools.rst
index e1770c8087a40997d7fcf2029b496f51d627ab91..c3fe3b7d82ee6330fdcfe78d6638d368422887ef 100644 (file)
--- a/doc/rados/operations/pools.rst
+++ b/doc/rados/operations/pools.rst
@@ -25,7 +25,10 @@ Pools provide:
   resources. When setting up multiple pools, set an appropriate number of PGs
   for each pool and for the cluster as a whole. Each PG belongs to a specific
   pool: when multiple pools use the same OSDs, make sure that the **sum** of PG
-  replicas per OSD is in the desired PG-per-OSD target range. 
+  replicas per OSD is in the desired PG-per-OSD target range. See :ref:`Setting
+  the Number of Placement Groups <setting the number of placement groups>` for
+  instructions on how to manually set the number of placement groups per pool
+  (this procedure works only when the autoscaler is not used).
 
 - **CRUSH Rules**: When data is stored in a pool, the placement of the object
   and its replicas (or chunks, in the case of erasure-coded pools) in your