doc/cephadm/services: Correct indentation in osd.rst

Signed-off-by: Anthony D'Atri <anthonyeleven@users.noreply.github.com>
(cherry picked from commit 7b5f73f4c17acc7cd0aab87db528e5232c8f05e1)

diff --git a/doc/cephadm/services/osd.rst b/doc/cephadm/services/osd.rst
index 56646e1c92979ce757b4ac62bd070c336cb7d528..6b1ab7bfc3a46d3806a546fdb0d848c094e48166 100644 (file)
--- a/doc/cephadm/services/osd.rst
+++ b/doc/cephadm/services/osd.rst
@@ -6,9 +6,10 @@ OSD Service
 List Devices
 ============
 
-``ceph-volume`` scans each host in the cluster from time to time in order
-to determine which devices are present and whether they are eligible to be
-used as OSDs.
+``ceph-volume`` scans each host in the cluster periodically in order
+to determine the devices that are present and responsive. It is also
+determined whether each is eligible to be used for new OSDs in a block,
+DB, or WAL role.
 
 To print a list of devices discovered by ``cephadm``, run this command:
 
@@ -31,10 +32,7 @@ Example::
   srv-03    /dev/sdc  hdd   15R0A0P7FRD6         300G  Unknown  N/A    N/A    No
   srv-03    /dev/sdd  hdd   15R0A0O7FRD6         300G  Unknown  N/A    N/A    No
 
-Using the ``--wide`` option provides all details relating to the device,
-including any reasons that the device might not be eligible for use as an OSD.
-
-In the above example you can see fields named "Health", "Ident", and "Fault".
+In the above examples you can see fields named ``Health``, ``Ident``, and ``Fault``.
 This information is provided by integration with `libstoragemgmt`_. By default,
 this integration is disabled (because `libstoragemgmt`_ may not be 100%
 compatible with your hardware).  To make ``cephadm`` include these fields,
@@ -44,9 +42,20 @@ enable cephadm's "enhanced device scan" option as follows;
 
   ceph config set mgr mgr/cephadm/device_enhanced_scan true
 
+Note that the columns reported by ``ceph orch device ls`` may vary from release to
+release.
+
+The ``--wide`` option shows device details,
+including any reasons that the device might not be eligible for use as an OSD.
+Example (Reef)::
+
+  HOST               PATH          TYPE  DEVICE ID                                      SIZE  AVAILABLE  REFRESHED  REJECT REASONS
+  davidsthubbins    /dev/sdc       hdd   SEAGATE_ST20000NM002D_ZVTBJNGC17010W339UW25    18.1T  No         22m ago    Has a FileSystem, Insufficient space (<10 extents) on vgs, LVM detected
+  nigeltufnel       /dev/sdd       hdd   SEAGATE_ST20000NM002D_ZVTBJNGC17010C3442787    18.1T  No         22m ago    Has a FileSystem, Insufficient space (<10 extents) on vgs, LVM detected
+
 .. warning::
-    Although the libstoragemgmt library performs standard SCSI inquiry calls,
-    there is no guarantee that your firmware fully implements these standards.
+    Although the ``libstoragemgmt`` library issues standard SCSI (SES) inquiry calls,
+    there is no guarantee that your hardware and firmware properly implement these standards.
     This can lead to erratic behaviour and even bus resets on some older
     hardware. It is therefore recommended that, before enabling this feature,
     you test your hardware's compatibility with libstoragemgmt first to avoid
@@ -690,7 +699,11 @@ Additional Options
 There are multiple optional settings you can use to change the way OSDs are deployed.
 You can add these options to the base level of an OSD spec for it to take effect.
 
-This example would deploy all OSDs with encryption enabled.
+This example deploys encrypted OSDs on all unused drives.  Note that if Linux
+MD mirroring is used for the boot, ``/var/log``, or other volumes this spec *may*
+grab replacement or added drives before you can employ them for non-OSD purposes.
+The ``unmanaged`` attribute may be set to pause automatic deployment until you
+are ready.
 
 .. code-block:: yaml
 
@@ -819,18 +832,21 @@ This can be described with two layouts.
       data_devices:
         rotational: 1
       db_devices:
-        model: MC-55-44-XZ
-        limit: 2 # db_slots is actually to be favoured here, but it's not implemented yet
+        model: MC-55-44-XZ      # Select only this model for WAL+DB offload
+        limit: 2                # Select at most two for this purpose
+      db_slots: 5               # Chop the DB device into this many slices and
+                                #  use one for each of this many HDD OSDs
     ---
     service_type: osd
     service_id: osd_spec_ssd
     placement:
       host_pattern: '*'
-    spec:
+    spec:                       # This scenario is uncommon
       data_devices:
-        model: MC-55-44-XZ
-      db_devices:
-        vendor: VendorC
+        model: MC-55-44-XZ      # Select drives of this model for OSD data
+      db_devices:               # Select drives of this brand for WAL+DB. Since the
+        vendor: VendorC         #   data devices are SAS/SATA SSDs this would make sense for NVMe SSDs
+      db_slots: 2               # Back two slower SAS/SATA SSD data devices with each NVMe slice
 
 This would create the desired layout by using all HDDs as data_devices with two SSD assigned as dedicated db/wal devices.
 The remaining SSDs(10) will be data_devices that have the 'VendorC' NVMEs assigned as dedicated db/wal devices.