KVM: create qcow2 on CLVM

Author: weizhouapache

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/LibvirtStoragePool.java

@@ -130,8 +130,11 @@ public String getUuid() {
 
     @Override
     public PhysicalDiskFormat getDefaultFormat() {
-        if (getStoragePoolType() == StoragePoolType.CLVM || getStoragePoolType() == StoragePoolType.RBD || getStoragePoolType() == StoragePoolType.PowerFlex) {
+        if (getStoragePoolType() == StoragePoolType.RBD || getStoragePoolType() == StoragePoolType.PowerFlex) {
             return PhysicalDiskFormat.RAW;
+        } else if (getStoragePoolType() == StoragePoolType.CLVM) {
+            logger.info("CLVM storage pool, use qcow2 as default format");
+            return PhysicalDiskFormat.QCOW2;
         } else {
             return PhysicalDiskFormat.QCOW2;
         }

plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/storage/LibvirtStoragePoolTest.java

@@ -74,7 +74,7 @@ public void testDefaultFormats() {
         assertEquals(rbdPool.getStoragePoolType(), StoragePoolType.RBD);
 
         LibvirtStoragePool clvmPool = new LibvirtStoragePool(uuid, name, StoragePoolType.CLVM, adapter, storage);
-        assertEquals(clvmPool.getDefaultFormat(), PhysicalDiskFormat.RAW);
+        assertEquals(clvmPool.getDefaultFormat(), PhysicalDiskFormat.QCOW2);
         assertEquals(clvmPool.getStoragePoolType(), StoragePoolType.CLVM);
     }