CSTACKEX-18_2: fixing the behaviour for the VM level snapshot when quiecing is enabled and memory-disk is opted out

Author: rajiv-jain-netapp

engine/storage/snapshot/src/main/java/org/apache/cloudstack/storage/vmsnapshot/KvmFileBasedStorageVmSnapshotStrategy.java

@@ -503,8 +503,9 @@ protected VMSnapshot takeVmSnapshotInternal(VMSnapshot vmSnapshot, Map<VolumeInf
             return processCreateVmSnapshotAnswer(vmSnapshot, volumeInfoToSnapshotObjectMap, createDiskOnlyVMSnapshotAnswer, userVm, vmSnapshotVO, virtualSize, parentSnapshotVo);
         }
 
-        logger.error("Disk-only VM snapshot for VM [{}] failed{}.", userVm.getUuid(), answer != null ? " due to" + answer.getDetails() : "");
-        throw new CloudRuntimeException(String.format("Disk-only VM snapshot for VM [%s] failed.", userVm.getUuid()));
+        String details = answer != null ? answer.getDetails() : String.format("No answer received from host [%s]. The host may be unreachable.", hostId);
+        logger.error("Disk-only VM snapshot for VM [{}] failed due to: {}.", userVm.getUuid(), details);
+        throw new CloudRuntimeException(String.format("Disk-only VM snapshot for VM [%s] failed due to: %s.", userVm.getUuid(), details));
     }
 
     /**

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtCreateDiskOnlyVMSnapshotCommandWrapper.java

@@ -106,6 +106,10 @@ protected Answer takeDiskOnlyVmSnapshotOfRunningVm(CreateDiskOnlyVmSnapshotComma
                 return new CreateDiskOnlyVmSnapshotAnswer(cmd, false, errorMsg, null);
             }
             return new CreateDiskOnlyVmSnapshotAnswer(cmd, false, e.getMessage(), null);
+        } catch (Exception e) {
+            String errorMsg = String.format("Creation of disk-only VM snapshot for VM [%s] failed due to %s.", vmName, e.getMessage());
+            logger.error(errorMsg, e);
+            return new CreateDiskOnlyVmSnapshotAnswer(cmd, false, errorMsg, null);
         } finally {
             if (dm != null) {
                 try {
@@ -146,21 +150,13 @@ protected Answer takeDiskOnlyVmSnapshotOfStoppedVm(CreateDiskOnlyVmSnapshotComma
             }
         } catch (LibvirtException | QemuImgException e) {
             logger.error("Exception while creating disk-only VM snapshot for VM [{}]. Deleting leftover deltas.", vmName, e);
-            for (VolumeObjectTO volumeObjectTO : volumeObjectTos) {
-                Pair<Long, String> volSizeAndNewPath = mapVolumeToSnapshotSizeAndNewVolumePath.get(volumeObjectTO.getUuid());
-                PrimaryDataStoreTO primaryDataStoreTO = (PrimaryDataStoreTO) volumeObjectTO.getDataStore();
-                KVMStoragePool kvmStoragePool = storagePoolMgr.getStoragePool(primaryDataStoreTO.getPoolType(), primaryDataStoreTO.getUuid());
-
-                if (volSizeAndNewPath == null) {
-                    continue;
-                }
-                try {
-                    Files.deleteIfExists(Path.of(kvmStoragePool.getLocalPathFor(volSizeAndNewPath.second())));
-                } catch (IOException ex) {
-                    logger.warn("Tried to delete leftover snapshot at [{}] failed.", volSizeAndNewPath.second(), ex);
-                }
-            }
+            cleanupLeftoverDeltas(volumeObjectTos, mapVolumeToSnapshotSizeAndNewVolumePath, storagePoolMgr);
             return new Answer(cmd, e);
+        } catch (Exception e) {
+            logger.error("Unexpected exception while creating disk-only VM snapshot for VM [{}]. Deleting leftover deltas.", vmName, e);
+            cleanupLeftoverDeltas(volumeObjectTos, mapVolumeToSnapshotSizeAndNewVolumePath, storagePoolMgr);
+            return new CreateDiskOnlyVmSnapshotAnswer(cmd, false,
+                    String.format("Creation of disk-only VM snapshot for VM [%s] failed due to %s.", vmName, e.getMessage()), null);
         }
 
         return new CreateDiskOnlyVmSnapshotAnswer(cmd, true, null, mapVolumeToSnapshotSizeAndNewVolumePath);
@@ -192,6 +188,23 @@ protected Pair<String, Map<String, Pair<Long, String>>> createSnapshotXmlAndNewV
         return new Pair<>(snapshotXml, volumeObjectToNewPathMap);
     }
 
+    protected void cleanupLeftoverDeltas(List<VolumeObjectTO> volumeObjectTos, Map<String, Pair<Long, String>> mapVolumeToSnapshotSizeAndNewVolumePath, KVMStoragePoolManager storagePoolMgr) {
+        for (VolumeObjectTO volumeObjectTO : volumeObjectTos) {
+            Pair<Long, String> volSizeAndNewPath = mapVolumeToSnapshotSizeAndNewVolumePath.get(volumeObjectTO.getUuid());
+            PrimaryDataStoreTO primaryDataStoreTO = (PrimaryDataStoreTO) volumeObjectTO.getDataStore();
+            KVMStoragePool kvmStoragePool = storagePoolMgr.getStoragePool(primaryDataStoreTO.getPoolType(), primaryDataStoreTO.getUuid());
+
+            if (volSizeAndNewPath == null) {
+                continue;
+            }
+            try {
+                Files.deleteIfExists(Path.of(kvmStoragePool.getLocalPathFor(volSizeAndNewPath.second())));
+            } catch (IOException ex) {
+                logger.warn("Tried to delete leftover snapshot at [{}] failed.", volSizeAndNewPath.second(), ex);
+            }
+        }
+    }
+
     protected long getFileSize(String path) {
         return new File(path).length();
     }