Merge pull request #1066 from SUSE/asettle/backport

BACKPORT: Clarifying migrate DB commands (BSC#1211729)

xml/admin_saltcluster.xml

@@ -1218,7 +1218,7 @@ OSD_ID  HOST         STATE                    PG_COUNT  REPLACE  FORCE  STARTED_
    <para>
     DB device belongs to an OSD and stores its metadata (see <xref linkend="about-bluestore"/> for
     more details). There are several reasons why you may want to migrate an existing DB device to a
-    new one&mdash;for example, when OSDs have different DB sizes and you need to 
+    new one&mdash;for example, when OSDs have different DB sizes and you need to
     align them.
    </para>
    <tip>
@@ -1285,11 +1285,20 @@ devices                   /dev/vdb
     </step>
     <step>
      <para>
-      Migrate the DB device:
+       If the OSD does not have a preexisting DB device, create a new DB with the <command>new-db</command> command:
+     </para>
+<screen>[ceph: root@pacific /]ceph-volume lvm new-db --osd-id 0 \
+ --osd-fsid c276d2a4-5578-4847-94c6-8e2e6abf81c4 \
+ --target ceph-c3dc9227-ca3e-49bc-992c-00602cb3eec7/osd-db-b346b9ff-dbbe-40db-a95e-2419ccd31f2c</screen>
+     <para>
+       Then, migrate data using the <option>--from data</option> flag:
      </para>
 <screen>[ceph: root@pacific /]ceph-volume lvm migrate --osd-id 0 \
- --osd-fsid c276d2a4-5578-4847-94c6-8e2e6abf81c4 --from db \
+ --osd-fsid c276d2a4-5578-4847-94c6-8e2e6abf81c4 --from data \
  --target ceph-c3dc9227-ca3e-49bc-992c-00602cb3eec7/osd-db-b346b9ff-dbbe-40db-a95e-2419ccd31f2c</screen>
+     <para>
+       If the OSD does have a preexisting DB device, migrate the DB using the <option>--from db</option> flag:
+     </para>
     </step>
     <step>
      <para>