GabrielBrascher commented on a change in pull request #2997: Allow KVM VM live migration with ROOT volume on file storage type URL: https://github.com/apache/cloudstack/pull/2997#discussion_r241115787
########## File path: engine/storage/datamotion/src/main/java/org/apache/cloudstack/storage/motion/KvmNonManagedStorageDataMotionStrategy.java ########## @@ -0,0 +1,145 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.apache.cloudstack.storage.motion; + +import java.io.File; +import java.util.Map; +import java.util.Set; + +import javax.inject.Inject; + +import org.apache.cloudstack.engine.subsystem.api.storage.DataStore; +import org.apache.cloudstack.engine.subsystem.api.storage.StrategyPriority; +import org.apache.cloudstack.engine.subsystem.api.storage.TemplateDataFactory; +import org.apache.cloudstack.engine.subsystem.api.storage.TemplateInfo; +import org.apache.cloudstack.engine.subsystem.api.storage.VolumeInfo; +import org.apache.cloudstack.storage.datastore.db.StoragePoolVO; +import org.springframework.stereotype.Component; + +import com.cloud.agent.api.Answer; +import com.cloud.agent.api.MigrateCommand; +import com.cloud.agent.api.MigrateCommand.MigrateDiskInfo; +import com.cloud.agent.api.storage.CreateAnswer; +import com.cloud.agent.api.storage.CreateCommand; +import com.cloud.agent.api.to.VirtualMachineTO; +import com.cloud.host.Host; +import com.cloud.hypervisor.Hypervisor.HypervisorType; +import com.cloud.storage.DataStoreRole; +import com.cloud.storage.DiskOfferingVO; +import com.cloud.storage.Storage.StoragePoolType; +import com.cloud.storage.VolumeVO; +import com.cloud.utils.exception.CloudRuntimeException; +import com.cloud.vm.DiskProfile; + +/** + * Extends {@link StorageSystemDataMotionStrategy}, allowing KVM hosts to migrate VMs with the ROOT volume on a non managed local storage pool. + * As {@link StorageSystemDataMotionStrategy} is considering KVM, this implementation also migrates only from/to KVM hosts. + */ +@Component +public class KvmNonManagedStorageDataMotionStrategy extends StorageSystemDataMotionStrategy { + + @Inject + private TemplateDataFactory templateDataFactory; + + /** + * Uses the canHandle from the Super class {@link StorageSystemDataMotionStrategy}. If the storage pool is of file and the internalCanHandle from {@link StorageSystemDataMotionStrategy} CANT_HANDLE, returns the StrategyPriority.HYPERVISOR strategy priority. otherwise returns CANT_HANDLE. + * Note that the super implementation (override) is called by {@link #canHandle(Map, Host, Host)} which ensures that {@link #internalCanHandle(Map)} will be executed only if the source host is KVM. + */ + @Override + protected StrategyPriority internalCanHandle(Map<VolumeInfo, DataStore> volumeMap) { + if (super.internalCanHandle(volumeMap) == StrategyPriority.CANT_HANDLE) { Review comment: Thanks, @rhtyd. That was my first idea as well. ``` if (super.internalCanHandle(volumeMap) == StrategyPriority.HIGHEST) { return StrategyPriority.CANT_HANDLE; } else { Set<VolumeInfo> volumeInfoSet = volumeMap.keySet(); for (VolumeInfo volumeInfo : volumeInfoSet) { StoragePoolVO storagePoolVO = _storagePoolDao.findById(volumeInfo.getPoolId()); if (storagePoolVO.getPoolType() != StoragePoolType.Filesystem && storagePoolVO.getPoolType() != StoragePoolType.NetworkFilesystem) { return StrategyPriority.CANT_HANDLE; } } return StrategyPriority.HYPERVISOR; } ``` However, this approach would ignore cases where the `super.internalCanHandle(volumeMap)` returns the following `StrategyPriority`: `DEFAULT`, `HYPERVISOR`, or `PLUGIN`. Thus, I decided to be safe and use the `super.internalCanHandle(volumeMap) == StrategyPriority.CANT_HANDLE` conditional. One second approach could be considering all non desired alternatives with an `OR`. However, it makes the code ugly and yet error prone, in case of a new StrategyPriority is adopted. ``` if (super.internalCanHandle(volumeMap) == StrategyPriority.HIGHEST || super.internalCanHandle(volumeMap) == StrategyPriority.DEFAULT || super.internalCanHandle(volumeMap) == StrategyPriority.PLUGIN) { return StrategyPriority.CANT_HANDLE; } else { ... } ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
