doc: Update mclock-config-ref doc steps to override osd max iops capacity.

Update the steps in the mclock config reference document to manually
override an OSDs max IOPS capacity. Provide information on the alternative
ways to override the osd_mclock_max_capacity_iops_[hdd,ssd] options for
an OSD.

Fixes: https://tracker.ceph.com/issues/52025
Signed-off-by: Sridhar Seshasayee <sseshasa@redhat.com>

diff --git a/doc/rados/configuration/mclock-config-ref.rst b/doc/rados/configuration/mclock-config-ref.rst
index 9e16ee2db0262a3932a20d02ca8e0aa7bdbca6c5..4c1f40d3be433f25a632c89f1860a1049baf173b 100644 (file)
--- a/doc/rados/configuration/mclock-config-ref.rst
+++ b/doc/rados/configuration/mclock-config-ref.rst
@@ -151,14 +151,14 @@ command:
 
   .. prompt:: bash #
 
-    ceph config set [global,osd] osd_mclock_profile <value>
+    ceph config set osd.N osd_mclock_profile <value>
 
-For example, to change the profile to allow faster recoveries, the following
-command can be used to switch to the *high_recovery_ops* profile:
+For example, to change the profile to allow faster recoveries on "osd.0", the
+following command can be used to switch to the *high_recovery_ops* profile:
 
   .. prompt:: bash #
 
-    ceph config set osd osd_mclock_profile high_recovery_ops
+    ceph config set osd.0 osd_mclock_profile high_recovery_ops
 
 .. note:: The *custom* profile is not recommended unless you are an advanced
           user.
@@ -179,9 +179,9 @@ cluster is brought up by using the following command:
 
   .. prompt:: bash #
 
-    ceph config show osd.x osd_mclock_max_capacity_iops_[hdd, ssd]
+    ceph config show osd.N osd_mclock_max_capacity_iops_[hdd, ssd]
 
-For example, the following command shows the max capacity for osd.0 on a Ceph
+For example, the following command shows the max capacity for "osd.0" on a Ceph
 node whose underlying device type is SSD:
 
   .. prompt:: bash #
@@ -196,6 +196,11 @@ Steps to Manually Benchmark an OSD (Optional)
           capacity already determined automatically during OSD initialization.
           Otherwise, you may skip this section entirely.
 
+.. tip:: If you have already determined the benchmark data and wish to manually
+         override the max osd capacity for an OSD, you may skip to section
+         `Specifying  Max OSD Capacity`_.
+
+
 Any existing benchmarking tool can be used for this purpose. In this case, the
 steps use the *Ceph OSD Bench* command described in the next section. Regardless
 of the tool/command used, the steps outlined further below remain the same.
@@ -285,28 +290,25 @@ Specifying  Max OSD Capacity
 ````````````````````````````
 
 The steps in this section may be performed only if you want to override the
-max osd capacity automatically determined during OSD initialization. The option
-``osd_mclock_max_capacity_iops_[hdd, ssd]`` can be set by running the
+max osd capacity automatically set during OSD initialization. The option
+``osd_mclock_max_capacity_iops_[hdd, ssd]`` for an OSD can be set by running the
 following command:
 
   .. prompt:: bash #
 
-     ceph config set [global,osd] osd_mclock_max_capacity_iops_[hdd,ssd] <value>
+     ceph config set osd.N osd_mclock_max_capacity_iops_[hdd,ssd] <value>
 
-For example, the following command sets the max capacity for all the OSDs in a
-Ceph node whose underlying device type is SSDs:
-
-  .. prompt:: bash #
-
-    ceph config set osd osd_mclock_max_capacity_iops_ssd 25000
-
-To set the capacity for a specific OSD (for example "osd.0") whose underlying
-device type is HDD, use a command like this:
+For example, the following command sets the max capacity for a specific OSD
+(say "osd.0") whose underlying device type is HDD to 350 IOPS:
 
   .. prompt:: bash #
 
     ceph config set osd.0 osd_mclock_max_capacity_iops_hdd 350
 
+Alternatively, you may specify the max capacity for OSDs within the Ceph
+configuration file under the respective [osd.N] section. See
+:ref:`ceph-conf-settings` for more details.
+
 
 .. index:: mclock; config settings