oVirt engine version is 4.4.7.6-1.el8. cinderlib version is 3.0.0. cinder version is openstack-victoria. Below is the log that occurred while creating template from snapshot of the vm that uses mbs disk. (In /var/log/ovirt-engine/engine.log file) 2021-07-14 19:51:09,853+09 INFO [org.ovirt.engine.core.bll.AddVmTemplateFromSnapshotCommand] (default task-8) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Lock Acquired to object 'EngineLock:{exclusiveLocks='[t=TEMPLATE_NAME, 0474ad3a-86fc-4520-8028-63b89e5f075b=TEMPLATE]', sharedLocks='[f9c7a106-2855-4f3a-ac05-31aa316fb7bd=VM]'}' 2021-07-14 19:51:10,006+09 INFO [org.ovirt.engine.core.bll.AddVmTemplateFromSnapshotCommand] (default task-8) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Running command: AddVmTemplateFromSnapshotCommand internal: false. Entities affected : ID: 4ca6e0e8-e3a4-11eb-8830-480fcf63834f Type: StoragePoolAction group CREATE_TEMPLATE with role type USER 2021-07-14 19:51:10,306+09 INFO [org.ovirt.engine.core.bll.storage.disk.CreateAllTemplateDisksFromSnapshotCommand] (default task-8) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Running command: CreateAllTemplateDisksFromSnapshotCommand internal: true. 2021-07-14 19:51:10,399+09 INFO [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (default task-8) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] EVENT_ID: USER_ADD_VM_TEMPLATE(48), Creation of Template t from VM <UNKNOWN> was initiated by admin@internal-authz. 2021-07-14 19:51:11,363+09 INFO [org.ovirt.engine.core.bll.ConcurrentChildCommandsExecutionCallback] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-49) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Command 'CreateAllTemplateDisksFromSnapshot' id: '71a7d2b9-97c8-4f82-bd3c-98f4b85b5fe8' child commands '[]' executions were completed, status 'SUCCEEDED' 2021-07-14 19:51:12,641+09 INFO [org.ovirt.engine.core.bll.SerialChildCommandsExecutionCallback] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-65) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Command 'AddVmTemplateFromSnapshot' (id: '1bd7da61-39e5-483c-a16a-8f9d3d5d71aa') waiting on child command id: '71a7d2b9-97c8-4f82-bd3c-98f4b85b5fe8' type:'CreateAllTemplateDisksFromSnapshot' to complete 2021-07-14 19:51:12,761+09 INFO [org.ovirt.engine.core.bll.storage.disk.CreateAllTemplateDisksFromSnapshotCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-65) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Ending command 'org.ovirt.engine.core.bll.storage.disk.CreateAllTemplateDisksFromSnapshotCommand' successfully. 2021-07-14 19:51:13,874+09 ERROR [org.ovirt.engine.core.bll.storage.disk.image.TransferDiskImageCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-42) [c2e68590-a1f1-4538-8210-542e395cbe0a] Finalizing failed transfer. Download disk 'GlanceDisk-34bec3e' (disk id: '373b681a-847d-44c5-a63e-fc890cd48020', image id: '30c80886-060b-4458-b303-cb2a978cc8a0') 2021-07-14 19:51:13,874+09 WARN [org.ovirt.engine.core.bll.storage.disk.image.TransferDiskImageCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-42) [c2e68590-a1f1-4538-8210-542e395cbe0a] Failed to stop image transfer session. Ticket does not exist for image '373b681a-847d-44c5-a63e-fc890cd48020' 2021-07-14 19:51:14,119+09 INFO [org.ovirt.engine.core.bll.SerialChildCommandsExecutionCallback] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-42) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Command 'AddVmTemplateFromSnapshot' id: '1bd7da61-39e5-483c-a16a-8f9d3d5d71aa' child commands '[71a7d2b9-97c8-4f82-bd3c-98f4b85b5fe8]' executions were completed, status 'SUCCEEDED' 2021-07-14 19:51:15,386+09 INFO [org.ovirt.engine.core.bll.AddVmTemplateFromSnapshotCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-15) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Ending command 'org.ovirt.engine.core.bll.AddVmTemplateFromSnapshotCommand' successfully. 2021-07-14 19:51:15,424+09 INFO [org.ovirt.engine.core.bll.AddVmTemplateFromSnapshotCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-15) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] Lock freed to object 'EngineLock:{exclusiveLocks='[t=TEMPLATE_NAME, 0474ad3a-86fc-4520-8028-63b89e5f075b=TEMPLATE]', sharedLocks='[f9c7a106-2855-4f3a-ac05-31aa316fb7bd=VM]'}' 2021-07-14 19:51:15,649+09 INFO [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-15) [83fa8cd5-d49f-4753-bf0e-5219d1be431f] EVENT_ID: USER_ADD_VM_TEMPLATE_FINISHED_SUCCESS(51), Creation of Template t from VM <UNKNOWN> has been completed. Below is the log that occurred while creating new vm using template. (In /var/log/ovirt-engine/engine.log file) 2021-07-14 19:53:44,010+09 INFO [org.ovirt.engine.core.bll.RunVmCommand] (default task-7) [3db584e0-37f8-4d73-b6e8-92cb8a3eab11] Lock Acquired to object 'EngineLock:{exclusiveLocks='[95dc79af-b873-4838-9d49-260cef4a87c1=VM]', sharedLocks=''}' 2021-07-14 19:53:44,042+09 ERROR [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (default task-7) [3db584e0-37f8-4d73-b6e8-92cb8a3eab11] EVENT_ID: USER_FAILED_RUN_VM(54), Failed to run VM vm2 due to a failed validation: [Cannot run VM without at least one bootable disk. Alternatives: - Create a disk for this VM, and rerun the VM. - Change the boot sequence using the Edit VM command (Boot Option Sub-Tab). - Use the 'Run Once' command to select a different boot option and rerun the VM.] (User: admin@internal-authz). 2021-07-14 19:53:44,042+09 WARN [org.ovirt.engine.core.bll.RunVmCommand] (default task-7) [3db584e0-37f8-4d73-b6e8-92cb8a3eab11] Validation of action 'RunVm' failed for user admin@internal-authz. Reasons: VAR__ACTION__RUN,VAR__TYPE__VM,VM_CANNOT_RUN_FROM_DISK_WITHOUT_DISK 2021-07-14 19:53:44,042+09 INFO [org.ovirt.engine.core.bll.RunVmCommand] (default task-7) [3db584e0-37f8-4d73-b6e8-92cb8a3eab11] Lock freed to object 'EngineLock:{exclusiveLocks='[95dc79af-b873-4838-9d49-260cef4a87c1=VM]', sharedLocks=''}' During the above process, there is no log in /var/log/ovirt-engine/cinderlib/cinderlib.log file.