CSTACKEX-212: fix for snapshot failure for attached cs volumes nfs an…

server/src/main/java/com/cloud/storage/VolumeApiServiceImpl.java

@@ -1099,7 +1099,32 @@ private VolumeVO createVolumeOnStoragePool(Long volumeId, Long storageId) throws
         if (createVolumeResult.isFailed()) {
             throw new CloudRuntimeException("Volume creation on storage failed: " + createVolumeResult.getResult());
         }
-        return _volsDao.findById(volumeInfo.getId());
+        VolumeVO volVO = _volsDao.findById(volumeInfo.getId());
+        if (volVO.getFormat() == null) {
+            HypervisorType hyperType = storagePool.getHypervisor();
+            ImageFormat format = getSupportedImageFormatForHypervisor(hyperType);
+            if (format != null) {
+                volVO.setFormat(format);
+                _volsDao.update(volVO.getId(), volVO);
+            }
+        }
+        return volVO;
+    }
+
+    private ImageFormat getSupportedImageFormatForHypervisor(HypervisorType hyperType) {
+        if (hyperType == HypervisorType.XenServer) {
+            return ImageFormat.VHD;
+        } else if (hyperType == HypervisorType.KVM) {
+            return ImageFormat.QCOW2;
+        } else if (hyperType == HypervisorType.VMware) {
+            return ImageFormat.OVA;
+        } else if (hyperType == HypervisorType.Ovm) {
+            return ImageFormat.RAW;
+        } else if (hyperType == HypervisorType.Hyperv) {
+            return ImageFormat.VHDX;
+        } else {
+            return null;
+        }
     }
 
     @Override