HDDS-619. hdds.db.profile should not be tagged as a required setting & should default to DISK. Contributed by Dinesh Chitlangia.

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/HddsConfigKeys.java

@@ -72,7 +72,7 @@ public final class HddsConfigKeys {
 
   // DB Profiles used by ROCKDB instances.
   public static final String HDDS_DB_PROFILE = "hdds.db.profile";
-  public static final DBProfile HDDS_DEFAULT_DB_PROFILE = DBProfile.SSD;
+  public static final DBProfile HDDS_DEFAULT_DB_PROFILE = DBProfile.DISK;
 
   // Once a container usage crosses this threshold, it is eligible for
   // closing.

hadoop-hdds/common/src/main/resources/ozone-default.xml

@@ -1184,8 +1184,8 @@
 
   <property>
     <name>hdds.db.profile</name>
-    <value>SSD</value>
-    <tag>OZONE, OM, PERFORMANCE, REQUIRED</tag>
+    <value>DISK</value>
+    <tag>OZONE, OM, PERFORMANCE</tag>
     <description>This property allows user to pick a configuration
     that tunes the RocksDB settings for the hardware it is running
     on. Right now, we have SSD and DISK as profile options.</description>